Adjust reported CPU speed

Round reported CPU Mhz up if  within 20hz of next MHz increment

Source/HBIOS/hbios.asm

@@ -5173,7 +5173,11 @@ HB_CPUSPD1:
 	LD	(CB_CPUKHZ),HL
 	LD	DE,1000
 	CALL	DIV16
-	LD	A,C
+	LD	DE,980			; ROUND MHZ UP
+	XOR	A			; IF WITHIN 20HZ
+	SBC	HL,DE
+	CCF
+	ADC	A,C
 	LD	(CB_CPUMHZ),A
 ;
 	RET