xen-platform: use builtin_pci_driver

Use builtin_pci_driver() helper to simplify the code.

Signed-off-by: Geliang Tang <geliangtang@gmail.com>
Reviewed-by: Juergen Gross <jgross@suse.com>
Signed-off-by: Juergen Gross <jgross@suse.com>
1 file changed