ARM: mach-shmobile: sh7372 clock fixes

Fixes for the sh7372 clock framework:
 - remove unused #include <linux/platform_device.h>
 - add sh7372 prefix to user modifiable root clocks
 - put modifiable root clock prototypes in header file
 - fix off-by-one id error on VEU MSTP clocks
 - make arrays static

Signed-off-by: Magnus Damm <damm@opensource.se>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>