ath6kl: don't set hi_refclk_hz if hardware version doesn't need it
ath6kl: don't set hi_refclk_hz if hardware version doesn't need it

Needed for ar6004 hw3.0 support.

Signed-off-by: Kalle Valo <7081a7d99b8c74c0698a728df19e3915a995d7e1@qca.qualcomm.com>

KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs