No need to have an OMAP prefix on these SoCs that are in the family
but arent' really called OMAP.

Simple rename: CONFIG_SOC_OMAPTI81XX --> CONFIG_SOC_TI81XX

No functional change.
Signed-off-by: NKevin Hilman <khilman@ti.com>
Acked-by: NVaibhav Hiremath <hvaibhav@ti.com>
Signed-off-by: NTony Lindgren <tony@atomide.com>