ath5k: Fix bad udelay calls on AR5210 code

 * Fix bad udelay calls (using > 2000us) in AR5210 code and clean up
 some bits on nic_reset (AR5210 support is still in bad shape)

 Changes-licensed-under: ISC
Signed-off-by: Nick Kossifidis <mickflemm@gmail.com>

Signed-off-by: John W. Linville <linville@tuxdriver.com>