ssb: handle BCM43222 in pmu code.

The BCM43222 with the chipid 43222 or 0xa8d6 in hex do not need any
special handling in the pmu code. This prevents some error messages
being shown.

Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>
Signed-off-by: John W. Linville <linville@tuxdriver.com>