mesa/texcompress: Restrict FXT1 format to desktop GL subset

mesa/texcompress: Restrict FXT1 format to desktop GL subset

In agreement with the extension spec and commit
dd0eb004874645135b9aaac3ebbd0aaf274079ea, filter FXT1 formats to the
desktop GL profiles. Now we no longer advertise such formats as supported
in an ES context and then throw an INVALID_ENUM error when the client
tries to use such formats with CompressedTexImage2D.

Fixes the following 26 dEQP tests:
* dEQP-GLES2.functional.negative_api.texture.compressedteximage2d_invalid_border
* dEQP-GLES2.functional.negative_api.texture.compressedteximage2d_invalid_border_cube_neg_x
* dEQP-GLES2.functional.negative_api.texture.compressedteximage2d_invalid_border_cube_neg_y
* dEQP-GLES2.functional.negative_api.texture.compressedteximage2d_invalid_border_cube_neg_z
* dEQP-GLES2.functional.negative_api.texture.compressedteximage2d_invalid_border_cube_pos_x
* dEQP-GLES2.functional.negative_api.texture.compressedteximage2d_invalid_border_cube_pos_y
* dEQP-GLES2.functional.negative_api.texture.compressedteximage2d_invalid_border_cube_pos_z
* dEQP-GLES2.functional.negative_api.texture.compressedteximage2d_invalid_size
* dEQP-GLES2.functional.negative_api.texture.compressedteximage2d_level_max_cube_pos
* dEQP-GLES2.functional.negative_api.texture.compressedteximage2d_level_max_tex2d
* dEQP-GLES2.functional.negative_api.texture.compressedteximage2d_neg_level_cube
* dEQP-GLES2.functional.negative_api.texture.compressedteximage2d_neg_level_tex2d
* dEQP-GLES2.functional.negative_api.texture.compressedteximage2d_neg_width_height_cube_neg_x
* dEQP-GLES2.functional.negative_api.texture.compressedteximage2d_neg_width_height_cube_neg_y
* dEQP-GLES2.functional.negative_api.texture.compressedteximage2d_neg_width_height_cube_neg_z
* dEQP-GLES2.functional.negative_api.texture.compressedteximage2d_neg_width_height_cube_pos_x
* dEQP-GLES2.functional.negative_api.texture.compressedteximage2d_neg_width_height_cube_pos_y
* dEQP-GLES2.functional.negative_api.texture.compressedteximage2d_neg_width_height_cube_pos_z
* dEQP-GLES2.functional.negative_api.texture.compressedteximage2d_neg_width_height_tex2d
* dEQP-GLES2.functional.negative_api.texture.compressedteximage2d_width_height_max_cube_neg_x
* dEQP-GLES2.functional.negative_api.texture.compressedteximage2d_width_height_max_cube_neg_y
* dEQP-GLES2.functional.negative_api.texture.compressedteximage2d_width_height_max_cube_neg_z
* dEQP-GLES2.functional.negative_api.texture.compressedteximage2d_width_height_max_cube_pos_x
* dEQP-GLES2.functional.negative_api.texture.compressedteximage2d_width_height_max_cube_pos_y
* dEQP-GLES2.functional.negative_api.texture.compressedteximage2d_width_height_max_cube_pos_z
* dEQP-GLES2.functional.negative_api.texture.compressedteximage2d_width_height_max_tex2d

v2. Use _mesa_is_desktop_gl() (Ilia, Ian)

Reviewed-by: Ian Romanick <ian.d.romanick@intel.com>
Signed-off-by: Nanley Chery <nanley.g.chery@intel.com>