With the egl::Image class now only storing the sized internal format,
some OpenGL ES 1.1 functionality broke because it was still expecting a
base format.

Change-Id: Ib41e91f371a06b2a09471ea45dd1f8f56b94091f
Reviewed-on: https://swiftshader-review.googlesource.com/17468Tested-by: Nicolas Capens <nicolascapens@google.com>
Reviewed-by: Alexis Hétu <sugoi@google.com>