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/nitrogen6q_defconfig b/configs/nitrogen6q_defconfig
index 6357776..10ab4b3 100644
--- a/configs/nitrogen6q_defconfig
+++ b/configs/nitrogen6q_defconfig
@@ -86,3 +86,4 @@
 CONFIG_SPLASH_SCREEN=y
 CONFIG_SPLASH_SCREEN_ALIGN=y
 CONFIG_VIDEO_BMP_GZIP=y
+CONFIG_VIDEO_BMP_RLE8=y