drm/amdkfd: gfx12.1 trap handler instruction fixup for VOP3PX

drm/amdkfd: gfx12.1 trap handler instruction fixup for VOP3PX

A trap may occur in the middle of VOP3PX instruction co-issue.
The PC would be restored incorrectly if left unmodified.

Identify this case by examining the instruction opcode and
rewind the PC 8 bytes if it occurs.

Signed-off-by: Jay Cornwall <jay.cornwall@amd.com>
Reviewed-by: Lancelot Six <lancelot.six@amd.com>
Reviewed-by: Vladimir Indic <vladimir.indic@amd.com>
Cc: Shweta Khatri <shweta.khatri@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>