rockchip: video: Kconfig: set MAX_XRES and MAX_YRES via Kconfig

This introduces two new Kconfig options that configure the maximum
allowable framebuffer size (i.e. the memory reservation/allocation for
the framebuffer):
 - VIDEO_ROCKCHIP_MAX_XRES
 - VIDEO_ROCKCHIP_MAX_YRES
The resulting memory allocation will cover 4 byte per pixel for these
resolutions.

Signed-off-by: Philipp Tomsich <philipp.tomsich@theobroma-systems.com>
Reviewed-by: Simon Glass <sjg@chromium.org>

drivers/video/rockchip/Kconfig

@@ -19,6 +19,24 @@ menuconfig VIDEO_ROCKCHIP
 	  This driver supports the on-chip video output device, and targets the
 	  Rockchip RK3288 and RK3399.
 
+config VIDEO_ROCKCHIP_MAX_XRES
+        int "Maximum horizontal resolution (for memory allocation purposes)"
+	depends on VIDEO_ROCKCHIP
+	default 1920
+	help
+	  The maximum horizontal resolution to support for the framebuffer.
+	  This configuration is used for reserving/allocating memory for the
+	  framebuffer during device-model binding/probing.
+
+config VIDEO_ROCKCHIP_MAX_YRES
+        int "Maximum vertical resolution (for memory allocation purposes)"
+	depends on VIDEO_ROCKCHIP
+	default 1080
+	help
+	  The maximum vertical resolution to support for the framebuffer.
+	  This configuration is used for reserving/allocating memory for the
+	  framebuffer during device-model binding/probing.
+
 if VIDEO_ROCKCHIP
 
 config DISPLAY_ROCKCHIP_EDP

drivers/video/rockchip/rk_vop.c

@@ -357,7 +357,8 @@ static int rk_vop_bind(struct udevice *dev)
 {
 	struct video_uc_platdata *plat = dev_get_uclass_platdata(dev);
 
-	plat->size = 1920 * 1200 * 4;
+	plat->size = 4 * (CONFIG_VIDEO_ROCKCHIP_MAX_XRES *
+			  CONFIG_VIDEO_ROCKCHIP_MAX_YRES);
 
 	return 0;
 }