arm64: add '#ifdef CONFIG_COMPAT' for aarch32_break_handler()

If 'COMPAT' not defined, aarch32_break_handler() cannot pass compiling,
and it can work independent with 'COMPAT', so remove dummy definition.

The related error:

  arch/arm64/kernel/debug-monitors.c:249:5: error: redefinition of ‘aarch32_break_handler’
  In file included from arch/arm64/kernel/debug-monitors.c:29:0:
  /root/linux-next/arch/arm64/include/asm/debug-monitors.h:89:12: note: previous definition of ‘aarch32_break_handler’ was here

Signed-off-by: Chen Gang <gang.chen@asianux.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

arch/arm64/include/asm/debug-monitors.h

@@ -83,14 +83,7 @@ static inline int reinstall_suspended_bps(struct pt_regs *regs)
 }
 #endif
 
-#ifdef CONFIG_COMPAT
 int aarch32_break_handler(struct pt_regs *regs);
-#else
-static int aarch32_break_handler(struct pt_regs *regs)
-{
-	return -EFAULT;
-}
-#endif
 
 #endif	/* __ASSEMBLY */
 #endif	/* __KERNEL__ */