Add a utility routine ps3_compare_firmware_version() to compare system
firmware versions.  Uses the existing ps3_get_firmware_version() routine.
Signed-off-by: NMasakazu Mokuno <mokuno@sm.sony.co.jp>
Signed-off-by: NGeoff Levand <geoffrey.levand@am.sony.com>
Signed-off-by: NPaul Mackerras <paulus@samba.org>