PWT buzzer driver: conditionalize on TARGET_HAS_BUZZER Here we add a new target config preprocessor symbol TARGET_HAS_BUZZER, currently defined for c11x and c139; later we also expect to have it on for FC Venus, and in FC Magnetite we are going to turn it on for target dsample, just for the sake of completeness and philosophical correctness.

#define	CONFIG_TARGET_C139	1
#define	CONFIG_TARGET_C1XX	1
#define	CONFIG_TARGET_COMPAL	1
#define	USE_TSPACT2_FOR_TXLOW	1
#define	GPIO1_SPEAKER_CTRL	0
#define	UARTFAX_CLASSIC_DTR_DCD	0
#define	TARGET_HAS_BUZZER	1