In Intel driver, the data with format DXGI_FORMAT_B5G6R5_UNORM will be
parsed incorrectly. According to
https://msdn.microsoft.com/en-us/library/windows/desktop/ff471324(v=vs.85).aspx
DXGI_FORMAT_B5G6R5_UNORM should be equivalent to D3DFMT_R5G6B5. However,
the data will be treated as B5G6R5 not R5G6B5.

This workaroud will disable B5G6R5 support when it's Intel driver.
By default, it will use R8G8B8A8 format.

BUG=chromium:644610
TEST=dEQP-GLES3.functional.fbo.blit.default_framebuffer.rgb565*

Change-Id: I9d64a9bcedf9247de6950d345ed2d3fb00170d30
Reviewed-on: https://chromium-review.googlesource.com/380421
Commit-Queue: Jamie Madill <jmadill@chromium.org>
Reviewed-by: Jamie Madill <jmadill@chromium.org>