staging: fsl-mc: drop a few useless #includes

Some #includes were needlessly done from header files. Drop them from
there and update the only .c file that implicitly needed one of those
#includes.

Signed-off-by: Laurentiu Tudor <laurentiu.tudor@nxp.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>