ARC: Reset: Use __builtin_arc_brk() instead of open-coded ASM

For quite some time we have a GCC's built-in which inserts BRK
instruction so let's use it instead of simple insertion of in-line
assembly.

Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>

arch/arc/lib/reset.c

@@ -12,7 +12,7 @@ int do_reset(cmd_tbl_t *cmdtp, int flag, int argc, char *const argv[])
 
 #ifdef DEBUG
 	/* Stop debug session here */
-	__asm__("brk");
+	__builtin_arc_brk();
 #endif
 	return 0;
 }