ath10k: remove 4-addr padding related hw_param configuration

hw_4addr_pad was added to handle different types of padding
in 4-address rx frame. But this padding is not very specific
to 4-address, it can happen even with three address + ethernet
decap mode. Since the  padding information can be obtained
through Rx desc for QCA99X0 and newer chips, this hw_param
is not needed any more.

Signed-off-by: Vasanthakumar Thiagarajan <vthiagar@qti.qualcomm.com>
Signed-off-by: Kalle Valo <kvalo@qca.qualcomm.com>