ath10k: increase BMI timeout

When testing a 9888 chipset NIC, I notice it often takes
almost 2 seconds, and then many times OTP fails, probably due
to the two-second timeout.

[ 2269.841842] ath10k_pci 0000:05:00.0: bmi cmd took: 1984 jiffies (HZ: 1000), rv: 0
[ 2273.608185] ath10k_pci 0000:05:00.0: bmi cmd took: 1986 jiffies (HZ: 1000), rv: 0
[ 2277.294732] ath10k_pci 0000:05:00.0: bmi cmd took: 1989 jiffies (HZ: 1000), rv: 0

So, increase the BMI timeout to 3 seconds.

Signed-off-by: Ben Greear <greearb@candelatech.com>
Signed-off-by: Kalle Valo <kvalo@qca.qualcomm.com>