lantiq: use nvmem for fritz 736x

lantiq: use nvmem for fritz 736x

Two use AR9287 and one AR9381. Both have different calibration sizes.
Move differences out of wifi node to make it clearer what's what.

qca,no-eeprom needs to stay for 7362sl as there's no nvmem equivalent
for caldata_extract_reverse

Signed-off-by: Rosen Penev <rosenp@gmail.com>
Link: https://github.com/openwrt/openwrt/pull/17278
Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>