px4_fmu-v2_default was already at 99.98% flash on main (1031972 of
1032192 bytes), leaving 220 bytes of headroom, so any change touching
common code overflows it.
The Septentrio driver was inherited by this board when it was split out
of the gps driver, rather than chosen for it, and it costs 12.5 KB here.
A high-end RTK receiver is an unlikely pairing with fmu-v2 anyway, and
the other v2 variants are overlays on this config, so all four regain
the same headroom:
default 100.03% -> 98.81%
fixedwing 99.59% -> 98.42%
multicopter 99.19% -> 98.02%
rover 97.86% -> 96.69%
It remains enabled on fmu-v3 and fmu-v4, which have 2 MB of flash.
Assisted-by: Claude:claude-opus-5
Signed-off-by: Julian Oes <julian@oes.ch>