ti: k3: drivers: ti_sci: Internalize raw get/set state functions

The raw get and set state functions for both devices and clocks
are only meant for use internal to the TI-SCI driver, the same
functionality is available from the other API that call into
these. Remove them from the external interface and make them
static scope to the driver.

Signed-off-by: Andrew F. Davis <afd@ti.com>