gpio: mvebu: update Armada XP per-CPU comment

Commit 2233bf7a ("gpio: mvebu: switch to regmap for register access")
introduced percpu_regs to replace percpu_membase. Update the comment to
match.

Cc: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
Fixes: 2233bf7a ("gpio: mvebu: switch to regmap for register access")
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Baruch Siach <baruch@tkos.co.il>
Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>

drivers/gpio/gpio-mvebu.c

@@ -78,8 +78,7 @@
 
 /*
  * The Armada XP has per-CPU registers for interrupt cause, interrupt
- * mask and interrupt level mask. Those are relative to the
- * percpu_membase.
+ * mask and interrupt level mask. Those are in percpu_regs range.
  */
 #define GPIO_EDGE_CAUSE_ARMADAXP_OFF(cpu) ((cpu) * 0x4)
 #define GPIO_EDGE_MASK_ARMADAXP_OFF(cpu)  (0x10 + (cpu) * 0x4)