m68k/mac: Kill psc_present

The presence of the Apple Peripheral System Controller (PSC) can be
tested for by just checking its base address pointer.

Signed-off-by: Geert Uytterhoeven <[e-mail]>

arch/m68k/include/asm/mac_psc.h

···
 #ifndef __ASSEMBLY__
 
 extern volatile __u8 *psc;
-extern int psc_present;
 
 extern void psc_register_interrupts(void);
 extern void psc_irq_enable(int);

arch/m68k/mac/macints.c

···
 		oss_register_interrupts();
 	else
 		via_register_interrupts();
-	if (psc_present)
+	if (psc)
 		psc_register_interrupts();
 	if (baboon_present)
 		baboon_register_interrupts();
···
 	case 4:
 	case 5:
 	case 6:
-		if (psc_present)
+		if (psc)
 			psc_irq_enable(irq);
 		else if (oss_present)
 			oss_irq_enable(irq);
···
 	case 4:
 	case 5:
 	case 6:
-		if (psc_present)
+		if (psc)
 			psc_irq_disable(irq);
 		else if (oss_present)
 			oss_irq_disable(irq);

arch/m68k/mac/psc.c

···
 
 #define DEBUG_PSC
 
-int psc_present;
 volatile __u8 *psc;
 EXPORT_SYMBOL_GPL(psc);
 
···
 {
 	int	i;
 
-	if (!psc_present) return;
+	if (!psc)
+		return;
+
 	for (i = 0x30 ; i < 0x70 ; i += 0x10) {
 		printk("PSC #%d:  IFR = 0x%02X IER = 0x%02X\n",
 			i >> 4,
···
 	 && macintosh_config->ident != MAC_MODEL_Q840)
 	{
 		psc = NULL;
-		psc_present = 0;
 		return;
 	}
 
···
 	 */
 
 	psc = (void *) PSC_BASE;
-	psc_present = 1;
 
 	printk("PSC detected at %p\n", psc);