drm/hx8357d: Avoid spamming logs if probe is deferred

The GPIO request can fail and probe may be deferred. Thus,
the error message may be printed again and again. Avoid
this by replacing DRM_DEV_ERROR() by dev_err_probe().

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Noralf Trønnes <noralf@tronnes.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20210421163157.50949-7-andriy.shevchenko@linux.intel.com