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/libretech-s912-pc_defconfig b/configs/libretech-s912-pc_defconfig
index 79b20e3..217fd74 100644
--- a/configs/libretech-s912-pc_defconfig
+++ b/configs/libretech-s912-pc_defconfig
@@ -74,4 +74,5 @@
 CONFIG_VIDEO_DT_SIMPLEFB=y
 CONFIG_SPLASH_SCREEN=y
 CONFIG_SPLASH_SCREEN_ALIGN=y
+CONFIG_VIDEO_BMP_RLE8=y
 CONFIG_OF_LIBFDT_OVERLAY=y