efi/bgrt: Drop __initdata from bgrt_image_size

bgrt_image_size is necessary to (optionally) show the boot graphics from
the efifb code. The efifb driver is a platform driver, using a normal
driver probe() driver callback. So even though it is always builtin it
cannot reference __initdata.
Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>

drivers/firmware/efi/efi-bgrt.c

@@ -20,7 +20,7 @@
 #include <linux/efi-bgrt.h>
 
 struct acpi_table_bgrt bgrt_tab;
-size_t __initdata bgrt_image_size;
+size_t bgrt_image_size;
 
 struct bmp_header {
 	u16 id;