soc: fsl: qe: simplify qe_ic_init()

qe_ic_init() takes a flags parameter, but all callers (including the
sole remaining one) have always passed 0. So remove that parameter and
simplify the body accordingly. We still explicitly initialize the
Interrupt Configuration Register (CICR) to its reset value of
all-zeroes, just in case the bootloader has played funny games.

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