Cleanup GPS compilation warnings from
ca746d2ff47c8eb589386045b91bbccdd76246d1
CC3D / NAZE - Adding support for hardware controlled inverter for use by
SBUS RX.
Fix PWM in RSSI - accidentally excluded when adding CJMCU support.
allow controlling external XOR gate connected to PB2 (BOOT1) to invert USART2_RX signal on F1. Currently used by sbus driver.
On second thought, no need to make inverter configurable. only sbus will use it, and the driver can set inversion automatically.
Fix build relating to inverter/pwm rssi compiler errors.