pan/bi: Decode FMA_SHIFT properly

The shift-bitwise ops are fairly configurable, let's decode this the
right way. Choo choo.

Signed-off-by: Alyssa Rosenzweig <alyssa.rosenzweig@collabora.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/4025>
2 files changed