ipq40xx: fix 5Ghz tx/rx power on the ASUS MAP-AC2200

ipq40xx: fix 5Ghz tx/rx power on the ASUS MAP-AC2200

The ASUS MAP-AC2200 suffers from a lower transmit/receive
signal power as compared to the stock firmware.

Upon investigation, it was discovered that stock firmware from
the GPL_MAP-AC2200_3.0.0.4.384.46249-g97d05bb.tar archive.
set the following GPIOs in "release/src/router/rc/init.c".

GPIO 44 and 46 have to be set to output high
GPIO 45 and 47 have to be set to output low

Here are some results, after activating the relevant
gpios through cmdline:

<https://forum.openwrt.org/t/asus-map-ac2200-low-transmit-receive-signal-5ghz/69005/12>

THX @ slh

Fixes: 9ad3967f140 ("ipq40xx: add support for ASUS Lyra")
Signed-off-by: Yushi Nishida <kyro2man@gmx.net>
[slightly rewritten commit, added missing <>)
Signed-off-by: Christian Lamparter <chunkeey@gmail.com>