ARM: locomo: fix locomolcd_power declaration

The locomolcd driver has one remaining missing-prototype warning:

drivers/video/backlight/locomolcd.c:83:6: error: no previous prototype for 'locomolcd_power' [-Werror=missing-prototypes]

There is in fact an unused prototype with a similar name in a global
header, so move the actual one there and remove the old one.

Link: https://lore.kernel.org/r/20230927194844.680771-1-arnd@kernel.orgSigned-off-by: Arnd Bergmann <arnd@arndb.de>

arch/arm/include/asm/hardware/locomo.h

@@ -195,7 +195,7 @@ struct locomo_driver {
 
 #define LOCOMO_DRIVER_NAME(_ldev) ((_ldev)->dev.driver->name)
 
-void locomo_lcd_power(struct locomo_dev *, int, unsigned int);
+extern void locomolcd_power(int on);
 
 int locomo_driver_register(struct locomo_driver *);
 void locomo_driver_unregister(struct locomo_driver *);

arch/arm/mach-sa1100/include/mach/collie.h

@@ -16,8 +16,6 @@
 
 #include "hardware.h" /* Gives GPIO_MAX */
 
-extern void locomolcd_power(int on);
-
 #define COLLIE_SCOOP_GPIO_BASE	(GPIO_MAX + 1)
 #define COLLIE_GPIO_CHARGE_ON	(COLLIE_SCOOP_GPIO_BASE + 0)
 #define COLLIE_SCP_DIAG_BOOT1	SCOOP_GPCR_PA12