[ARM] tegra: Add clock support

v2: fixes from Russell King:
	- include linux/io.h instead of asm/io.h
	- fix whitespace in Kconfig
	- Use spin_lock_init to initialize lock
	- Return -ENOSYS instead of BUG for unimplemented clock ops
	- Use proper return values in tegra2 clock ops
    additional changes:
	- Rename some clocks to match dev_ids
	- add rate propagation
	- add debugfs entries
	- add support for clock listed in clk_lookup under multiple dev_ids
v3:
	- Replace per-clock locking with global clock lock
	- Autodetect clock state on init
	- Let clock dividers pick next lower possible frequency
	- Add support for clock init tables
	- Minor bug fixes
	- Fix checkpatch issues

Signed-off-by: Colin Cross <ccross@android.com>
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index 56d2c42..43aad7a 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -568,6 +568,7 @@
 	select GENERIC_CLOCKEVENTS
 	select GENERIC_GPIO
 	select HAVE_CLK
+	select COMMON_CLKDEV
 	select ARCH_HAS_BARRIERS if CACHE_L2X0
 	help
 	  This enables support for NVIDIA Tegra based systems (Tegra APX,