MIPS: BCM63XX: Introduce bcm_readq & bcm_writeq.

Needed for upcoming 6368 CPU support.

[ralf@linux-mips.org: Changed function names as per Sergei's comments.]
Signed-off-by: Maxime Bizon <mbizon@freebox.fr>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/2896/Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

arch/mips/include/asm/mach-bcm63xx/bcm63xx_io.h

@@ -49,9 +49,11 @@
 #define bcm_readb(a)	(*(volatile unsigned char *)	BCM_REGS_VA(a))
 #define bcm_readw(a)	(*(volatile unsigned short *)	BCM_REGS_VA(a))
 #define bcm_readl(a)	(*(volatile unsigned int *)	BCM_REGS_VA(a))
+#define bcm_readq(a)	(*(volatile u64 *)		BCM_REGS_VA(a))
 #define bcm_writeb(v, a) (*(volatile unsigned char *) BCM_REGS_VA((a)) = (v))
 #define bcm_writew(v, a) (*(volatile unsigned short *) BCM_REGS_VA((a)) = (v))
 #define bcm_writel(v, a) (*(volatile unsigned int *) BCM_REGS_VA((a)) = (v))
+#define bcm_writeq(v, a) (*(volatile u64 *) BCM_REGS_VA((a)) = (v))
 
 /*
  * IO helpers to access register set for current CPU