svga: Force an RGBA view creation for an RGBA resource
svga: Force an RGBA view creation for an RGBA resource

glXCreatePixmap() may specify a GLX_TEXTURE_FORMAT_RGB_EXT format
for an RGBA resource, causing us to create an RGBX view for an
RGBA resource, a combination vgpu10 does not support.

When this is detected, change the request to create an RGBA view
instead.

Reviewed-by: Brian Paul <3cb4e1df5ec4da2c7c4af7c52cec8cf340a55a10@vmware.com>

metora/MesaGLSLCompiler,metora/MesaGLSLCompiler,metora/MesaGLSLCompiler