ARM: OMAP4+: Make control module register structure generic

A seperate omap_sys_ctrl_regs structure is defined for
omap4 & 5. If there is any change in control module for
any of the ES versions, a new structure needs to be created.
In order to remove this dependency, making the register
structure generic for all the omap4+ boards.

Signed-off-by: R Sricharan <r.sricharan@ti.com>
Signed-off-by: Lokesh Vutla <lokeshvutla@ti.com>
Reviewed-by: Tom Rini <trini@ti.com>