PCI: hv: Move hypercall related definitions into tlfs header

Currently HVCALL_RETARGET_INTERRUPT and HV_PARTITION_ID_SELF are defined
in pci-hyperv.c. However, similar to other hypercall related
definitions, it makes more sense to put them in the tlfs header file.

Besides, these definitions are arch-dependent, so for the support of
virtual PCI on non-x86 archs in the future, move them into arch-specific
tlfs header file.

Signed-off-by: Boqun Feng (Microsoft) <boqun.feng@gmail.com>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Reviewed-by: Andrew Murray <amurray@thegoodpenguin.co.uk>
Reviewed-by: Dexuan Cui <decui@microsoft.com>