arm64: move early_brk64 prototype to header

The prototype used for calling early_brk64() is in the file that calls
it, which is the wrong place, as it is not included for the definition:

arch/arm64/kernel/traps.c:1100:12: error: no previous prototype for 'early_brk64' [-Werror=missing-prototypes]

Move it to an appropriate header instead.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Kees Cook <keescook@chromium.org>
Acked-by: Ard Biesheuvel <ardb@kernel.org>
Link: https://lore.kernel.org/r/20230516160642.523862-15-arnd@kernel.org
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

Author: arndb

arch/arm64/include/asm/traps.h

@@ -29,6 +29,8 @@ void arm64_force_sig_fault(int signo, int code, unsigned long far, const char *s
 void arm64_force_sig_mceerr(int code, unsigned long far, short lsb, const char *str);
 void arm64_force_sig_ptrace_errno_trap(int errno, unsigned long far, const char *str);
 
+int early_brk64(unsigned long addr, unsigned long esr, struct pt_regs *regs);
+
 /*
  * Move regs->pc to next instruction and do necessary setup before it
  * is executed.

arch/arm64/mm/fault.c

@@ -886,9 +886,6 @@ void do_sp_pc_abort(unsigned long addr, unsigned long esr, struct pt_regs *regs)
 }
 NOKPROBE_SYMBOL(do_sp_pc_abort);
 
-int __init early_brk64(unsigned long addr, unsigned long esr,
-		       struct pt_regs *regs);
-
 /*
  * __refdata because early_brk64 is __init, but the reference to it is
  * clobbered at arch_initcall time.