clk: sunxi: Add a driver for the PLL2

The PLL2 on the A10 and later SoCs is the clock used for all the audio
related operations.

This clock has a somewhat complex output tree, with three outputs (2X, 4X
and 8X) with a fixed divider from the base clock, and an output (1X) with a
post divider.

However, we can simplify things since the 1X divider can be fixed, and we
end up by having a base clock not exposed to any device (or at least
directly, since the 4X output doesn't have any divider), and 4 fixed
divider clocks that will be exposed.

This clock seems to have been introduced, at least in this form, in the
revision B of the A10, but we don't have any information on the clock used
on the revision A.

Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Reviewed-by: Chen-Yu Tsai <wens@csie.org>
diff --git a/include/dt-bindings/clock/sun4i-a10-pll2.h b/include/dt-bindings/clock/sun4i-a10-pll2.h
new file mode 100644
index 0000000..071c811
--- /dev/null
+++ b/include/dt-bindings/clock/sun4i-a10-pll2.h
@@ -0,0 +1,53 @@
+/*
+ * Copyright 2015 Maxime Ripard
+ *
+ * Maxime Ripard <maxime.ripard@free-electrons.com>
+ *
+ * This file is dual-licensed: you can use it either under the terms
+ * of the GPL or the X11 license, at your option. Note that this dual
+ * licensing only applies to this file, and not this project as a
+ * whole.
+ *
+ *  a) This file is free software; you can redistribute it and/or
+ *     modify it under the terms of the GNU General Public License as
+ *     published by the Free Software Foundation; either version 2 of the
+ *     License, or (at your option) any later version.
+ *
+ *     This file is distributed in the hope that it will be useful,
+ *     but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *     GNU General Public License for more details.
+ *
+ * Or, alternatively,
+ *
+ *  b) Permission is hereby granted, free of charge, to any person
+ *     obtaining a copy of this software and associated documentation
+ *     files (the "Software"), to deal in the Software without
+ *     restriction, including without limitation the rights to use,
+ *     copy, modify, merge, publish, distribute, sublicense, and/or
+ *     sell copies of the Software, and to permit persons to whom the
+ *     Software is furnished to do so, subject to the following
+ *     conditions:
+ *
+ *     The above copyright notice and this permission notice shall be
+ *     included in all copies or substantial portions of the Software.
+ *
+ *     THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+ *     EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES
+ *     OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+ *     NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT
+ *     HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY,
+ *     WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ *     FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
+ *     OTHER DEALINGS IN THE SOFTWARE.
+ */
+
+#ifndef __DT_BINDINGS_CLOCK_SUN4I_A10_PLL2_H_
+#define __DT_BINDINGS_CLOCK_SUN4I_A10_PLL2_H_
+
+#define SUN4I_A10_PLL2_1X	0
+#define SUN4I_A10_PLL2_2X	1
+#define SUN4I_A10_PLL2_4X	2
+#define SUN4I_A10_PLL2_8X	3
+
+#endif /* __DT_BINDINGS_CLOCK_SUN4I_A10_PLL2_H_ */