On OMAP secure/emulation devices, certain APIs are exported by secure
code. Add an infrastructure so that relevant operations on secure
devices can be implemented using it.

While at this, rename omap44xx-smc.S to omap-smc.S since the common APIs
can be used on other OMAP's too.
Signed-off-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Acked-by: Jean Pihet <j-pihet@ti.com>
Reviewed-by: Kevin Hilman <khilman@ti.com>
Tested-by: Vishwanath BS <vishwanath.bs@ti.com>
Signed-off-by: Kevin Hilman <khilman@ti.com>