drm/panel: ilitek-ili9881c: Fix warning with GPIO controllers that sleep

The ilitek-ili9881c controls the reset GPIO using the non-sleeping
gpiod_set_value() function. This complains loudly when the GPIO
controller needs to sleep. As the caller can sleep, use
gpiod_set_value_cansleep() to fix the issue.
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Neil Armstrong <neil.armstrong@linaro.org>
Link: https://lore.kernel.org/r/20240317154839.21260-1-laurent.pinchart@ideasonboard.comSigned-off-by: Neil Armstrong <neil.armstrong@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20240317154839.21260-1-laurent.pinchart@ideasonboard.com

drivers/gpu/drm/panel/panel-ilitek-ili9881c.c

@@ -1276,10 +1276,10 @@ static int ili9881c_prepare(struct drm_panel *panel)
 	msleep(5);
 
 	/* And reset it */
-	gpiod_set_value(ctx->reset, 1);
+	gpiod_set_value_cansleep(ctx->reset, 1);
 	msleep(20);
 
-	gpiod_set_value(ctx->reset, 0);
+	gpiod_set_value_cansleep(ctx->reset, 0);
 	msleep(20);
 
 	for (i = 0; i < ctx->desc->init_length; i++) {
@@ -1334,7 +1334,7 @@ static int ili9881c_unprepare(struct drm_panel *panel)
 
 	mipi_dsi_dcs_enter_sleep_mode(ctx->dsi);
 	regulator_disable(ctx->power);
-	gpiod_set_value(ctx->reset, 1);
+	gpiod_set_value_cansleep(ctx->reset, 1);
 
 	return 0;
 }