ARM: OMAP: Make plat/fpga.h local to arch/arm/plat-omap

There's no need to have this file in plat/fpga.h. We can
make it local to plat-omap replacing fpga_read/write
functions directly with readb/writeb as that's how
they are already defined in fpga.h.

Note that 2420 based H4 is also using the fpga, so let's
keep the led support around in plat-omap until we flip
over mach-omap2 to device tree.

Cc: Tomi Valkeinen <tomi.valkeinen@ti.com>
Cc: Florian Tobias Schandinat <FlorianSchandinat@gmx.de>
Cc: linux-fbdev@vger.kernel.org
Cc: Felipe Balbi <balbi@ti.com>
Cc: linux-usb@vger.kernel.org
Signed-off-by: Tony Lindgren <tony@atomide.com>
diff --git a/arch/arm/mach-omap1/common.h b/arch/arm/mach-omap1/common.h
index c2552b2..a65f50a 100644
--- a/arch/arm/mach-omap1/common.h
+++ b/arch/arm/mach-omap1/common.h
@@ -38,6 +38,7 @@
 #endif
 
 #ifdef CONFIG_ARCH_OMAP15XX
+void omap1510_fpga_init_irq(void);
 void omap15xx_map_io(void);
 #else
 static inline void omap15xx_map_io(void)