mmc: slot-gpio: Allow non-sleeping GPIO ro

mmc: slot-gpio: Allow non-sleeping GPIO ro

This change uses the appropriate _cansleep or non-sleeping API for
reading GPIO read-only state. This allows users with GPIOs that
never sleepbeing called in atomic context.

Implement the same mechanism as in commit 52af318c93e97 ("mmc: Allow
non-sleeping GPIO cd").

Signed-off-by: Alexander Stein <alexander.stein@ew.tq-group.com>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20240206083912.2543142-1-alexander.stein@ew.tq-group.com
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>