This patch updates the common platform files with AM335X device
support (AM33XX family).

The approach taken in this patch is,
AM33XX device will be considered as OMAP3 variant, and a separate
SoC class created for AM33XX family of devices with a subclass type
for AM335X device, which is newly added device in the family.

This means, cpu_is_omap34xx(), cpu_is_am33xx() and cpu_is_am335x()
checks will return success on AM335X device.
A kernel config option CONFIG_SOC_OMAPAM33XX is added under OMAP3
to include support for AM33XX build.

Also, cpu_mask and RATE_IN_XXX flags have crossed 8 bit hence
struct clksel_rate.flags, struct prcm_config.flags and cpu_mask
are changed to u16 from u8.

Signed-off-by: Afzal Mohammed <afzal@ti.com>
Signed-off-by: Vaibhav Hiremath <hvaibhav@ti.com>
Cc: Hemant Pedanekar <hemantp@ti.com>
[tony@atomide.com: left out CK_AM33XX for now]
Signed-off-by: Tony Lindgren <tony@atomide.com>