configs: migrate CONFIG_VIDEO_BMP_RLE8 to defconfigs

Done with:
./tools/moveconfig.py VIDEO_BMP_RLE8

Signed-off-by: Patrick Delaunay <patrick.delaunay@st.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
diff --git a/configs/mx51evk_defconfig b/configs/mx51evk_defconfig
index 343816f..72b1417 100644
--- a/configs/mx51evk_defconfig
+++ b/configs/mx51evk_defconfig
@@ -39,4 +39,5 @@
 CONFIG_USB_ETHER_SMSC95XX=y
 CONFIG_SYS_WHITE_ON_BLACK=y
 CONFIG_SPLASH_SCREEN=y
+CONFIG_VIDEO_BMP_RLE8=y
 CONFIG_OF_LIBFDT=y