x86/domain: factor out pv_domain_initialise
Lump everything PV related in arch_domain_create into
pv_domain_initialise.
Though domcr_flags and config are not necessary, the new function is
given those to match hvm counterpart.
Since it cleans up after itself there is no need to clean up in
arch_domain_create in case of failure. Remove the initialiser of rc in
arch_domain_create.
No functional change.
Signed-off-by: Wei Liu <wei.liu2@citrix.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>