Adding support for setting the coverage class in some cases broke
association and data transfer, as it overwrote the initial ACK timeout
value from the initvals with a smaller value.
I don't know why the new value works in 5 GHz (matches the initval
there), but not in 2.4 GHz (initvals use 64us here), so until the
problem is fully understood, the value should be increased again.
Signed-off-by: Felix Fietkau <nbd@openwrt.org> Signed-off-by: John W. Linville <linville@tuxdriver.com>