fate: Explicitly specify the rgb555le pixel format for the mss2 rgb555 tests

This fixes these fate tests on big endian.

Signed-off-by: Martin Storsjö <martin@martin.st>

tests/fate/microsoft.mak

@@ -8,10 +8,10 @@ FATE_MSS2 += fate-mss2-pals
 fate-mss2-pals: CMD = framecrc -i $(TARGET_SAMPLES)/mss2/rlepals.wmv
 
 FATE_MSS2 += fate-mss2-rgb555
-fate-mss2-rgb555: CMD = framecrc -i $(TARGET_SAMPLES)/mss2/rle555.wmv
+fate-mss2-rgb555: CMD = framecrc -i $(TARGET_SAMPLES)/mss2/rle555.wmv -pix_fmt rgb555le
 
 FATE_MSS2 += fate-mss2-rgb555s
-fate-mss2-rgb555s: CMD = framecrc -i $(TARGET_SAMPLES)/mss2/rle555s.wmv
+fate-mss2-rgb555s: CMD = framecrc -i $(TARGET_SAMPLES)/mss2/rle555s.wmv -pix_fmt rgb555le
 
 FATE_MSS2 += fate-mss2-wmv
 fate-mss2-wmv: CMD = framecrc -i $(TARGET_SAMPLES)/mss2/msscreencodec.wmv -an -frames 100