drm/nouveau/bios: fix i2c table parsing for dcb 4.1
drm/nouveau/bios: fix i2c table parsing for dcb 4.1

Code before looked only at bit 31 to decide if a port is unused.
However dcb 4.1 spec says 0x1F in bits 31-27 and 26-22 means unused.

This fixed hdmi monitor detection on GM206.

Signed-off-by: Ben Skeggs <d9f27fb07c1e9f131223ad827fa5179f3846c30b@redhat.com>

KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs