MLK-19083 drm/imx: lcdif: remove untrue condition for pixel format set

MLK-19083 drm/imx: lcdif: remove untrue condition for pixel format set

After supporting DISPMIX power domain, the LCDIF runtime
resume callback always write '0' to 'LCDIF_CTRL' register
which will clear previous pixel format related setting.
So the previous condition by comparing format change for
setting pixel format during plane atomic update is not
true anymore.

Signed-off-by: Fancy Fang <chen.fang@nxp.com>
(cherry picked from commit 5f84c69799456f28fd8182fd156e9067921e9a4e)
(cherry picked from commit 364fd1879c587fbdb80aa290df54609c30de7ef8)