clk: bcm2835: Mark the VPU clock as critical

The VPU clock is also the clock for our AXI bus, so we really can't
disable it.  This might have happened during boot if, for example,
uart1 (aux_uart clock) probed and was then disabled before the other
consumers of the VPU clock had probed.

Signed-off-by: Eric Anholt <eric@anholt.net>
Acked-by: Martin Sperl <kernel@martin.sperl.org>
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>
diff --git a/drivers/clk/bcm/clk-bcm2835.c b/drivers/clk/bcm/clk-bcm2835.c
index 7a79708..d9db03c 100644
--- a/drivers/clk/bcm/clk-bcm2835.c
+++ b/drivers/clk/bcm/clk-bcm2835.c
@@ -443,6 +443,8 @@
 	/* Number of fractional bits in the divider */
 	u32 frac_bits;
 
+	u32 flags;
+
 	bool is_vpu_clock;
 	bool is_mash_clock;
 };
@@ -1230,7 +1232,7 @@
 	init.parent_names = parents;
 	init.num_parents = data->num_mux_parents;
 	init.name = data->name;
-	init.flags = CLK_IGNORE_UNUSED;
+	init.flags = data->flags | CLK_IGNORE_UNUSED;
 
 	if (data->is_vpu_clock) {
 		init.ops = &bcm2835_vpu_clock_clk_ops;
@@ -1649,6 +1651,7 @@
 		.div_reg = CM_VPUDIV,
 		.int_bits = 12,
 		.frac_bits = 8,
+		.flags = CLK_IS_CRITICAL,
 		.is_vpu_clock = true),
 
 	/* clocks with per parent mux */