wifi: rt2x00: don't run Rt5592 IQ calibration on MT7620

The function rt2800_iq_calibrate is intended for Rt5592 only.
Don't call it for MT7620 which has it's own calibration functions.

Reported-by: Serge Vasilugin <vasilugin@yandex.ru>
Signed-off-by: Daniel Golle <daniel@makrotopia.org>
Signed-off-by: Kalle Valo <kvalo@kernel.org>
Link: https://lore.kernel.org/r/31a1c34ddbd296b82f38c18c9ae7339059215fdc.1663445157.git.daniel@makrotopia.org