drivers: i2c: nrfx: Prevent transfer overlapping

I2C transfers could simultaneous be called that would
cause an inconsistent state in NRFX I2C state (and HW).
The NRFX TWI driver would expect to be in state
`NRFX_DRV_STATE_INITIALIZED` while being in state
`NRFX_DRV_STATE_POWERED_ON`.

Signed-off-by: Olivier Martin <olivier.martin@proglove.de>
2 files changed