reset: socfpga: declare socfpga_reset_init in a header file

Avoid declaring extern functions in c files. To make sure function
definition and usage don't get out of sync, declare socfpga_reset_init
in a common header.
Suggested-by: NStephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: NPhilipp Zabel <p.zabel@pengutronix.de>
Acked-by: NDinh Nguyen <dinguyen@kernel.org>

arch/arm/mach-socfpga/socfpga.c

@@ -19,6 +19,7 @@
 #include <linux/of_irq.h>
 #include <linux/of_platform.h>
 #include <linux/reboot.h>
+#include <linux/reset/socfpga.h>
 
 #include <asm/hardware/cache-l2x0.h>
 #include <asm/mach/arch.h>
@@ -32,8 +33,6 @@ void __iomem *rst_manager_base_addr;
 void __iomem *sdr_ctl_base_addr;
 unsigned long socfpga_cpu1start_addr;
 
-extern void __init socfpga_reset_init(void);
-
 static void __init socfpga_sysmgr_init(void)
 {
 	struct device_node *np;

drivers/reset/reset-socfpga.c

@@ -11,6 +11,7 @@
 #include <linux/of_address.h>
 #include <linux/platform_device.h>
 #include <linux/reset-controller.h>
+#include <linux/reset/socfpga.h>
 #include <linux/slab.h>
 #include <linux/spinlock.h>
 #include <linux/types.h>
@@ -18,7 +19,6 @@
 #include "reset-simple.h"
 
 #define SOCFPGA_NR_BANKS	8
-void __init socfpga_reset_init(void);
 
 static int a10_reset_init(struct device_node *np)
 {

include/linux/reset/socfpga.h

+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __LINUX_RESET_SOCFPGA_H__
+#define __LINUX_RESET_SOCFPGA_H__
+
+void __init socfpga_reset_init(void);
+
+#endif /* __LINUX_RESET_SOCFPGA_H__ */