Revert "xen/domctl: Introduce XEN_DOMCTL_CDF_vpci flag"

Revert "xen/domctl: Introduce XEN_DOMCTL_CDF_vpci flag"

This reverts commit 2075b410ee8087662c880213c3aca196fb7ade22.

During the discussion [1] that took place after
the patch was merged it was agreed that it should
be reverted to avoid introducing a bad interface.

Furthermore, the patch rejected usage of flag
XEN_DOMCTL_CDF_vpci for x86 which is not true
as it should be set for dom0 PVH.

Due to XEN_DOMCTL_CDF_vpmu being introduced after
XEN_DOMCTL_CDF_vpci, modify its bit position
from 8 to 7.

[1] https://marc.info/?t=163354215300039&r=1&w=2

Signed-off-by: Michal Orzel <michal.orzel@arm.com>
Acked-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Christian Lindig <christian.lindig@citrix.com<mailto:christian.lindig@citrix.com>>
Acked-by: Julien Grall <jgrall@amazon.com>
Reviewed-by: Bertrand Marquis <bertrand.marquis@arm.com>