OMAP2/3 clock: clean up omap*_clk_arch_init()

In the OMAP3xxx clock code, remove the #ifdef CONFIG_ARCH_OMAP3 in
clock34xx.c, since this file is only compiled for OMAP3xxx builds.  Also,
rename omap2_clk_arch_init in this file to omap3xxx_clk_arch_init() to
pave the way for multi-OMAP kernels.  Ensure that it is not executed
on non-OMAP3xxx systems.

In the OMAP2xxx clock code, rename omap2_clk_arch_init in this file to
omap2xxx_clk_arch_init() to pave the way for multi-OMAP kernels.
Ensure that it is not executed on non-OMAP2xxx systems.

Signed-off-by: Paul Walmsley <paul@pwsan.com>
diff --git a/arch/arm/mach-omap2/clock2xxx.c b/arch/arm/mach-omap2/clock2xxx.c
index e5b9851..b7e81ec 100644
--- a/arch/arm/mach-omap2/clock2xxx.c
+++ b/arch/arm/mach-omap2/clock2xxx.c
@@ -101,11 +101,14 @@
  * Switch the MPU rate if specified on cmdline.
  * We cannot do this early until cmdline is parsed.
  */
-static int __init omap2_clk_arch_init(void)
+static int __init omap2xxx_clk_arch_init(void)
 {
 	struct clk *virt_prcm_set, *sys_ck, *dpll_ck, *mpu_ck;
 	unsigned long sys_ck_rate;
 
+	if (!cpu_is_omap24xx())
+		return 0;
+
 	if (!mpurate)
 		return -EINVAL;
 
@@ -129,6 +132,6 @@
 
 	return 0;
 }
-arch_initcall(omap2_clk_arch_init);
+arch_initcall(omap2xxx_clk_arch_init);