MLK-19400-2 drm/imx: sec-dsim_imx: alter 'rpm_suspended' to a counter

MLK-19400-2 drm/imx: sec-dsim_imx: alter 'rpm_suspended' to a counter

Since the DSIM's runtime PM suspend() and resume() callbacks
are also called during system PM suspend() and resume(), it
is necessary to use a counter to record the suspended depth,
and 'rpm_suspended' field can be used as this purpose which
can help to detect and avoid runtime suspend and resume calls
mismatch caused problems, by changing the 'rpm_suspended' to
be an atomic integer from a boolean type.

Signed-off-by: Fancy Fang <chen.fang@nxp.com>
(cherry picked from commit 91a8e6c8f63db328fbc752b1659bdaa67ee5c8d5)
(cherry picked from commit 09f6ef5494d5fec7e3949bd80e4b51200b60dee3)