gralloc: Fix inverted colors on BRGA

Don't assume any 32bpp mode is RGBX.
This is a forward-port of
commit f50b075a8b88eff482628e8ab62a04539117c7ea

Signed-off-by: Bernhard Rosenkraenzer <Bernhard.Rosenkranzer@linaro.org>
diff --git a/modules/gralloc/framebuffer.cpp b/modules/gralloc/framebuffer.cpp
index e0831df..a1ded49 100644
--- a/modules/gralloc/framebuffer.cpp
+++ b/modules/gralloc/framebuffer.cpp
@@ -330,7 +330,7 @@
         if (status >= 0) {
             int stride = m->finfo.line_length / (m->info.bits_per_pixel >> 3);
             int format = (m->info.bits_per_pixel == 32)
-                         ? HAL_PIXEL_FORMAT_RGBX_8888
+                         ? (m->info.red.offset ? HAL_PIXEL_FORMAT_BGRA_8888 : HAL_PIXEL_FORMAT_RGBX_8888)
                          : HAL_PIXEL_FORMAT_RGB_565;
             const_cast<uint32_t&>(dev->device.flags) = 0;
             const_cast<uint32_t&>(dev->device.width) = m->info.xres;