INT 80 - SoundBlaster SBFM driver - SET SYSTEM CLOCK RATE

	BX = 0003h
	AX = clock rate divisor (1193180 / desired frequency in Hertz)
	    FFFFh to restore to 18.2 Hz
SeeAlso: BX=0000h"SBFM",BX=0001h"SBFM",BX=0004h"SBFM"