mac80211: enable ath10k AHB support for QCA4019

mac80211: enable ath10k AHB support for QCA4019

This patch enables the ATH10K_AHB support for the QCA4019
devices on the AHB bus.

This patch also removes 936-ath10k_skip_otp_check.patch
because it breaks the AHB device identification.
"Patch is wrong. I find it frustrating OpenWRT/LEDE doesn't
try to work with upstream on ixing these things right."

[1] <https://www.mail-archive.com/ath10k@lists.infradead.org/msg05896.html>

It also limits ath10k memory hunger (This is a problem with 128MiB RAM)

Signed-off-by: Christian Lamparter <chunkeey@gmail.com>