ARM: OMAP5: Avoid writing into LDO SRAM bits

Writing magic bits into LDO SRAM was suggested only for OMAP5432
ES1.0. Now these are no longer applicable. Moreover these bits should
not be overwritten as they are loaded from EFUSE. So avoid
writing into these registers.

Boot tested on OMAP5432 ES2.0

Signed-off-by: Lokesh Vutla <lokeshvutla@ti.com>