implement PWT buzzer driver The piece implemented here is the low-level driver component; there will also be a higher-level buzzer melody player service, to be implemented in RiViera land, that will be the sole caller of PWT API functions provided by the present driver.

#define	CONFIG_TARGET_J100	1
#define	CONFIG_TARGET_COMPAL	1
#define	USE_TSPACT2_FOR_TXLOW	0
#define	GPIO1_SPEAKER_CTRL	0
#define	UARTFAX_CLASSIC_DTR_DCD	0