Remove FORMAT_A1R5G5B5 from EGL configs.

This is not a natively supported pixel format, thus causing a performance
penalty for conversion. It is not supported by Nexus 4 or 5. Android has
deprecated both 4444 and 5551 as HAL formats. Also, UNSIGNED_SHORT_5_5_5_1
has the alpha component in the least significant bit, whereas A1R5G5B5 has
alpha as the most significant bit.

Bug 27690616

Change-Id: I350f0e780cd87b8a626e2c8914a65c61dbf63258
Reviewed-on: https://swiftshader-review.googlesource.com/4960
Reviewed-by: Alexis Hétu <sugoi@google.com>
Reviewed-by: Nicolas Capens <capn@google.com>
Tested-by: Nicolas Capens <capn@google.com>

src/OpenGL/libEGL/Display.cpp

diff --git a/src/OpenGL/libEGL/Display.cpp b/src/OpenGL/libEGL/Display.cpp
index 8b53080..cbef7fd 100644
--- a/src/OpenGL/libEGL/Display.cpp
+++ b/src/OpenGL/libEGL/Display.cpp
@@ -119,7 +119,7 @@
 
     const sw::Format renderTargetFormats[] =
     {
-        sw::FORMAT_A1R5G5B5,
+	//	sw::FORMAT_A1R5G5B5,
     //  sw::FORMAT_A2R10G10B10,   // The color_ramp conformance test uses ReadPixels with UNSIGNED_BYTE causing it to think that rendering skipped a colour value.
         sw::FORMAT_A8R8G8B8,
         sw::FORMAT_A8B8G8R8,