soc: fsl: qe: qe.c: use of_property_read_* helpers

soc: fsl: qe: qe.c: use of_property_read_* helpers

Instead of manually doing of_get_property/of_find_property and reading
the value by assigning to a u32* or u64* and dereferencing, use the
of_property_read_* functions.

This make the code more readable, and more importantly, is required
for this to work correctly on little-endian platforms.

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