gpio: add protype for name_to_gpio

Signed-off-by: Jeroen Hofstee <jeroen@myspectrum.nl>
diff --git a/include/asm-generic/gpio.h b/include/asm-generic/gpio.h
index 1ebb9c7..347805e 100644
--- a/include/asm-generic/gpio.h
+++ b/include/asm-generic/gpio.h
@@ -193,4 +193,6 @@
 int gpio_lookup_name(const char *name, struct udevice **devp,
 		     unsigned int *offsetp, unsigned int *gpiop);
 
+int name_to_gpio(const char *name);
+
 #endif	/* _ASM_GENERIC_GPIO_H_ */