sf: Do not force the DT memory map size to exactly match the device

As long as the memory mapped size specifeid in the DT is the same or
bigger than the device size, it will work. So do not force the sizes
to be identical.
Signed-off-by: NPhil Edworthy <phil.edworthy@renesas.com>
Reviewed-by: NJagan Teki <jagan@openedev.com>

drivers/mtd/spi/spi_flash.c

@@ -985,7 +985,7 @@ int spi_flash_decode_fdt(const void *blob, struct spi_flash *flash)
 		return 0;
 	}
 
-	if (flash->size != size) {
+	if (flash->size > size) {
 		debug("%s: Memory map must cover entire device\n", __func__);
 		return -1;
 	}