ath9k_hw: update the chip tests for AR9003

The AR9003 family requires a change on the loop and can also skip
testing the PHY timing registers. This chip test can now be used
by all Atheros hardware families, including legacy. We can
eventually move this out to the generic ath module.

Signed-off-by: Senthil Balasubramanian <senthilkumar@atheros.com>
Signed-off-by: Luis R. Rodriguez <lrodriguez@atheros.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>