qualcommax: ipq50xx: correct fw memory mode for ipq5018 and qcn6122 wifi

qualcommax: ipq50xx: correct fw memory mode for ipq5018 and qcn6122 wifi

The reason fwmode 2 was used for ipq5018 and qcn6122 wifi was that
coldboot calibration doesn't work and causes the firmware to crach
during wifi bringup. Since coldboot calibration is now disabled in the
driver, all boards can now use their respective firmware memory mode, so
let's the property in all board DTS files accordingly.

Signed-off-by: George Moussalem <george.moussalem@outlook.com>
Link: https://github.com/openwrt/openwrt/pull/19083
Signed-off-by: Robert Marko <robimarko@gmail.com>