Use devfn_disable() for disabling a PCI device rather than
using `dev->enabled = 0`.
Also, use is_devfn_enabled() to get the device current state prior
updating the FSP-S UPD for XDCI.
TEST=FSP-S disabled XDCI when `xdci_can_enable` returns 0 and XDCI
is disabled at PCI enumeration `PCI: 00:14.1: enabled 0`.
Change-Id: I568cd39792eba1bbace4901e96d708d80f73c60a
Signed-off-by: Subrata Banik <subrata.banik@intel.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/55724
Reviewed-by: Furquan Shaikh <furquan@google.com>
Reviewed-by: Angel Pons <th3fanbus@gmail.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
1369544b3f