gpio/pl061: remove old comment

Since 3ab52475 (gpio: pl061: convert to use generic irq chip) we only have one
spinlock in struct pl061_gpio.

Cc: Rob Herring <rob.herring@calxeda.com>
Signed-off-by: NBaruch Siach <baruch@tkos.co.il>
Acked-by: NLinus Walleij <linus.walleij@linaro.org>
Signed-off-by: NGrant Likely <grant.likely@secretlab.ca>

drivers/gpio/gpio-pl061.c

@@ -48,12 +48,7 @@ struct pl061_context_save_regs {
 #endif
 
 struct pl061_gpio {
-	/* Each of the two spinlocks protects a different set of hardware
-	 * regiters and data structurs. This decouples the code of the IRQ from
-	 * the GPIO code. This also makes the case of a GPIO routine call from
-	 * the IRQ code simpler.
-	 */
-	spinlock_t		lock;		/* GPIO registers */
+	spinlock_t		lock;
 
 	void __iomem		*base;
 	int			irq_base;