MIPS: Alchemy: add gpio_request/gpio_free stubs for CONFIG_GPIOLIB=n

Some drivers use gpio_request/gpio_free regardless of whether
gpiolib is actually built;  add stubs to work around the ensuing
compile failures.
Signed-off-by: Manuel Lauss <manuel.lauss@gmail.com>
Tested-by: Florian Fainelli <florian@openwrt.org>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

arch/mips/include/asm/mach-au1x00/gpio-au1000.h

@@ -578,6 +578,15 @@ static inline int irq_to_gpio(int irq)
 	return alchemy_irq_to_gpio(irq);
 }
 
+static inline int gpio_request(unsigned gpio, const char *label)
+{
+	return 0;
+}
+
+static inline void gpio_free(unsigned gpio)
+{
+}
+
 #endif	/* !CONFIG_ALCHEMY_GPIO_INDIRECT */