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/sandbox_defconfig b/configs/sandbox_defconfig
index 6ac2919..b15b188 100644
--- a/configs/sandbox_defconfig
+++ b/configs/sandbox_defconfig
@@ -253,6 +253,7 @@
 CONFIG_OSD=y
 CONFIG_SANDBOX_OSD=y
 CONFIG_SPLASH_SCREEN_ALIGN=y
+CONFIG_VIDEO_BMP_RLE8=y
 CONFIG_W1=y
 CONFIG_W1_GPIO=y
 CONFIG_W1_EEPROM=y