mac80211: add ath11k AHB support
This is the follow up to the PCI support commit now providing support for
AHB variant as well, though currently only for ipq807x as that is only
OpenWrt supported SoC ath11k supports as well.
Currently, we are disabling coldboot calibration on ipq807x as it does not
work, there is a remoteproc bug that makes it come late out of reset so
disable coldboot until that is fixed.
Also, as ath11k is quite memory hungry, we are introducing a config option
to use the limits for 512MB of RAM, similar to what QCA does downstream but
in way simpler and cleaner way so that 512MB save some RAM.
512MB profile is also set as the default for now.
Signed-off-by: Robert Marko <robimarko@gmail.com>