sm501: Adjust endianness of pixel value in rectangle fill

The value from twoD_foreground (which is in host endian format) must
be converted to the endianness of the framebuffer (currently always
little endian) before it can be used to perform the fill operation.
Signed-off-by: NMarcus Comstedt <marcus@mc.pp.se>
Reviewed-by: NBALATON Zoltan <balaton@eik.bme.hu>
Reviewed-by: NPeter Maydell <peter.maydell@linaro.org>
Signed-off-by: NDavid Gibson <david@gibson.dropbear.id.au>

hw/display/sm501.c

@@ -39,6 +39,7 @@
 #include "hw/i2c/i2c-ddc.h"
 #include "qemu/range.h"
 #include "ui/pixel_ops.h"
+#include "qemu/bswap.h"
 
 /*
  * Status: 2010/05/07
@@ -812,9 +813,11 @@ static void sm501_2d_operation(SM501State *s)
             FILL_RECT(1, uint8_t);
             break;
         case 1:
+            color = cpu_to_le16(color);
             FILL_RECT(2, uint16_t);
             break;
         case 2:
+            color = cpu_to_le32(color);
             FILL_RECT(4, uint32_t);
             break;
         }