VMCI: Support upto 64-bit PPNs

Add support in the VMCI driver to handle upto 64-bit PPNs when the VMCI
device exposes the capability for 64-bit PPNs.

Reviewed-by: Adit Ranadive <aditr@vmware.com>
Reviewed-by: Jorgen Hansen <jhansen@vmware.com>
Signed-off-by: Vishnu Dasa <vdasa@vmware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>