physical: Use struct physical_ctx instead of passing args one by one.

A lot of the arguments fo certain functions were getting out of hand,
pass struct physical_ctx instead of fields from that struct. This
has the added benefit of having available anything that is
in struct physical_ctx without adding additional arguments.

Signed-off-by: Ales Musil <amusil@redhat.com>
Acked-by: Lorenzo Bianconi <lorenzo.bianconi@redhat.com>
Signed-off-by: Mark Michelson <mmichels@redhat.com>