drm/panfrost: devfreq: Don't display error for EPROBE_DEFER

drm/panfrost: devfreq: Don't display error for EPROBE_DEFER

Set a condition for the message of "Couldn't set OPP regulators" to not
display if the error code is EPROBE_DEFER. Note that I used an if
statement to capture the condition instead of the dev_err_probe
function because I didn't want to change the DRM_DEV_ERROR usage.

Signed-off-by: Chris Morgan <macromorgan@hotmail.com>
Reviewed-by: Steven Price <steven.price@arm.com>
Signed-off-by: Steven Price <steven.price@arm.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210721214830.25690-1-macroalpha82@gmail.com