drm/stm: move to devm_platform_ioremap_resource() usage

Replace platform_get_resource + devm_ioremap_resource
with just devm_platform_ioremap_resource()

Used Coccinelle to do this change. SmPl patch:
@rule_1@
identifier res;
expression ioremap_res;
identifier pdev;
@@
-struct resource *res;
...
-res = platform_get_resource(pdev,...);
-ioremap_res = devm_ioremap_resource(...);
+ioremap_res = devm_platform_ioremap_resource(pdev,0);

Cc: Yannick Fertre <yannick.fertre@foss.st.com>
Cc: Raphael Gallais-Pou <raphael.gallais-pou@foss.st.com>
Cc: Philippe Cornu <philippe.cornu@foss.st.com>
Acked-by: Raphael Gallais-Pou <raphael.gallais-pou@foss.st.com>
Signed-off-by: Anusha Srivatsa <asrivats@redhat.com>
Acked-by: Raphaël Gallais-Pou <raphael.gallais-pou@foss.st.com>
Link: https://lore.kernel.org/r/20250225-memory-drm-misc-next-v1-8-9d0e8761107a@redhat.com
Signed-off-by: Maxime Ripard <mripard@kernel.org>

Author: anushasrivats

drivers/gpu/drm/stm/ltdc.c

@@ -1900,7 +1900,6 @@ int ltdc_load(struct drm_device *ddev)
 	struct drm_panel *panel;
 	struct drm_crtc *crtc;
 	struct reset_control *rstc;
-	struct resource *res;
 	int irq, i, nb_endpoints;
 	int ret = -ENODEV;
 
@@ -1966,8 +1965,7 @@ int ltdc_load(struct drm_device *ddev)
 		reset_control_deassert(rstc);
 	}
 
-	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
-	ldev->regs = devm_ioremap_resource(dev, res);
+	ldev->regs = devm_platform_ioremap_resource(pdev, 0);
 	if (IS_ERR(ldev->regs)) {
 		DRM_ERROR("Unable to get ltdc registers\n");
 		ret = PTR_ERR(ldev->regs);