drm/amdkfd: Update SMI throttle event bitmask

Update Arcturus/Aldebaran thermal throttle SMI event path to use
ASIC-independent throttler bits when logging.

Signed-off-by: Graham Sider <Graham.Sider@amd.com>
Reviewed-by: Harish Kasiviswanathan <Harish.Kasiviswanathan@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>