EGL: two fixes for colorspace attribute handling

1) set EGL_BAD_ATTRIBUTE if enum is not any of the valid
   EGL_GL_COLORSPACE_* enums
2) in getDriverColorSpaces(), add colorspaces to the support
   list as long as extension is supported by vendor driver.
   Don't check format here and leave that to vendor drivers
   that support the extensions.

Test: NV regression testing including dEQP
Test: EGL_test --gtest_filter=EGLTest.EGLInvalidColorspaceAttribute
Test: EGL_test --gtest_filter=EGLTest.EGLUnsupportedColorspaceFormatCombo

Change-Id: I1397732ebc4df01070de1fec57ceabf9092b0bdf
Merged-In: I1397732ebc4df01070de1fec57ceabf9092b0bdf