mesa: allow multisample texture targets in [Get]TexParameter*

mesa: allow multisample texture targets in [Get]TexParameter*

ARB_texture_storage_multisample allows texture parameters to be
queried for TEXTURE_2D_MULTISAMPLE and TEXTURE_2D_MULTISAMPLE_ARRAY
targets.

Some parameters may also be set, with the following exceptions:

- TEXTURE_BASE_LEVEL may not be set to a nonzero value; generates
   INVALID_OPERATION

- any state which appears in the `per-sampler` state table may not
  be set; generates INVALID_OPERATION

V2: Don't introduce bogus handling of TEXTURE_MAX_LEVEL

Signed-off-by: Chris Forbes <chrisf@ijw.co.nz>
Reviewed-by: Eric Anholt <eric@anholt.net>
Reviewed-by: Brian Paul <brianp@vmware.com>