intel/gm45: Fix interpretation of VT-d disable bit

When configuring the GTT size for the integrated graphics, the state
of VT-d was read wrong. Bit 48 of CAPID0 (D0F0) is set when VT-d is
_disabled_.

In the log of a VT-d enabled roda/rk9 we have now:

[...]
VT-d enabled
[...]
IGD decoded, subtracting 32M UMA and 4M GTT
[...]

Without this patch, only 2M GTT were reported.

Change-Id: I87582c18f4769c2a05be86936d865c0d1fb35966
Signed-off-by: Nico Huber <nico.huber@secunet.com>
Reviewed-on: http://review.coreboot.org/3252
Tested-by: build bot (Jenkins)
Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>
1 file changed