video: Add a test for 16bpp BMP files

Add a compressed 16bpp BMP file and a test to cover this.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/configs/sandbox_flattree_defconfig b/configs/sandbox_flattree_defconfig
index f184723..f16d890 100644
--- a/configs/sandbox_flattree_defconfig
+++ b/configs/sandbox_flattree_defconfig
@@ -198,6 +198,7 @@
 CONFIG_OSD=y
 CONFIG_SANDBOX_OSD=y
 CONFIG_VIDEO_BMP_RLE8=y
+CONFIG_BMP_16BPP=y
 CONFIG_CMD_DHRYSTONE=y
 CONFIG_RSA_VERIFY_WITH_PKEY=y
 CONFIG_TPM=y