sh: boot: Add proper forward declarations

arch/sh/boot/compressed/misc.c:110:6: warning: no previous prototype for ‘ftrace_stub’ [-Wmissing-prototypes]
arch/sh/boot/compressed/misc.c:113:6: warning: no previous prototype for ‘arch_ftrace_ops_list_func’ [-Wmissing-prototypes]
arch/sh/boot/compressed/misc.c:123:6: warning: no previous prototype for ‘decompress_kernel’ [-Wmissing-prototypes]

Signed-off-by: Geert Uytterhoeven <[e-mail]>
Reviewed-by: John Paul Adrian Glaubitz <[e-mail]>
Link: https://lore.kernel.org/r/b7ea7[e-mail]
Signed-off-by: John Paul Adrian Glaubitz <[e-mail]>

arch/sh/boot/compressed/misc.c

···
 #include <asm/addrspace.h>
 #include <asm/page.h>
 
+#include "misc.h"
+
 /*
  * gzip declarations
  */

arch/sh/boot/compressed/misc.h

···
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef MISC_H
+#define MISC_H
+
+void arch_ftrace_ops_list_func(void);
+void decompress_kernel(void);
+void ftrace_stub(void);
+
+#endif /* MISC_H */