drm/msm: Use of_reserved_mem_region_to_resource() for "memory-region"

Use the newly added of_reserved_mem_region_to_resource() function to
handle "memory-region" properties.

The original code did not set 'zap_available' to false if
of_address_to_resource() failed which seems like an oversight.

Signed-off-by: Rob Herring (Arm) <[e-mail]>
Reviewed-by: Dmitry Baryshkov <[e-mail]>
Patchwork: https://patchwork.freedesktop.org/patch/662275/
Link: https://lore.kernel.org/r/[e-mail]
[DB: dropped part related to VRAM, no longer applicable]
Signed-off-by: Dmitry Baryshkov <[e-mail]>

drivers/gpu/drm/msm/adreno/adreno_gpu.c

···
 #include <linux/interconnect.h>
 #include <linux/firmware/qcom/qcom_scm.h>
 #include <linux/kernel.h>
-#include <linux/of_address.h>
+#include <linux/of_reserved_mem.h>
 #include <linux/pm_opp.h>
 #include <linux/slab.h>
 #include <linux/soc/qcom/mdt_loader.h>
···
 	struct device *dev = &gpu->pdev->dev;
 	const struct firmware *fw;
 	const char *signed_fwname = NULL;
-	struct device_node *np, *mem_np;
+	struct device_node *np;
 	struct resource r;
 	phys_addr_t mem_phys;
 	ssize_t mem_size;
···
 		return -ENODEV;
 	}
 
-	mem_np = of_parse_phandle(np, "memory-region", 0);
-	of_node_put(np);
-	if (!mem_np) {
+	ret = of_reserved_mem_region_to_resource(np, 0, &r);
+	if (ret) {
 		zap_available = false;
-		return -EINVAL;
-	}
-
-	ret = of_address_to_resource(mem_np, 0, &r);
-	of_node_put(mem_np);
-	if (ret)
 		return ret;
-
+	}
 	mem_phys = r.start;
 
 	/*