power: as3722: add as3722_ldo_set_voltage signature to header file

Just like the already present as3722_sd_set_voltage() add the currently
missing signature of the as3722_ldo_set_voltage() function to its header
file.

Signed-off-by: Marcel Ziswiler <marcel.ziswiler@toradex.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Tom Warren <twarren@nvidia.com>

include/power/as3722.h

@@ -25,5 +25,6 @@
 #define AS3722_GPIO_CONTROL_INVERT (1 << 7)
 
 int as3722_sd_set_voltage(struct udevice *dev, unsigned int sd, u8 value);
+int as3722_ldo_set_voltage(struct udevice *dev, unsigned int ldo, u8 value);
 
 #endif /* __POWER_AS3722_H__ */