soc: fsl: qe: merge qe_ic.h headers into qe_ic.c

The public qe_ic.h header is no longer included by anything but
qe_ic.c. Merge both headers into qe_ic.c, and drop the unused
constants.

Reviewed-by: Timur Tabi <timur@kernel.org>
Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Signed-off-by: Li Yang <leoyang.li@nxp.com>