mmc: rtsx: Use pm_runtime_{get,put}() to handle runtime PM

mmc: rtsx: Use pm_runtime_{get,put}() to handle runtime PM

Commit 5b4258f6721f ("misc: rtsx: rts5249 support runtime PM") doesn't
use pm_runtime_{get,put}() helpers when it should, so the RPM refcount
keeps at zero, hence its parent driver, rtsx_pci, has to do lots of
weird tricks to keep it from runtime suspending.

So use those helpers at right places to properly manage runtime PM.

Fixes: 5b4258f6721f ("misc: rtsx: rts5249 support runtime PM")
Cc: Ricky WU <ricky_wu@realtek.com>
Tested-by: Ricky WU <ricky_wu@realtek.com>
Signed-off-by: Kai-Heng Feng <kai.heng.feng@canonical.com>
Link: https://lore.kernel.org/r/20220125055010.1866563-1-kai.heng.feng@canonical.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>