radeonsi: fix detection of DRAW_INDIRECT_MULTI on SI

radeonsi: fix detection of DRAW_INDIRECT_MULTI on SI

The firmware version numbers for SI were wrong. The new numbers are probably
too conservative (we don't have a definitive answer by the firmware team),
but DRAW_INDIRECT_MULTI has been confirmed to work with these versions on
Tahiti (by Gustaw) and on Verde (by myself).

While this is technically adding a feature, it's a feature we thought we had
for a long time. The change is small enough and we're early enough in the 17.2
release cycle that it should still go in.

Reported-by: Gustaw Smolarczyk <wielkiegie@gmail.com>
Cc: 17.2 <mesa-stable@lists.freedesktop.org>
Acked-by: Alex Deucher <alexander.deucher@amd.com>
Reviewed-by: Marek Olšák <marek.olsak@amd.com>