ARM: tegra: Mark expected switch fall-through

Mark switch cases where we are expecting to fall through.

This patch fixes the following warning:

arch/arm/mach-tegra/reset.c: In function 'tegra_cpu_reset_handler_enable':
arch/arm/mach-tegra/reset.c:72:3: warning: this statement may fall through [-Wimplicit-fallthrough=]
   tegra_cpu_reset_handler_set(reset_address);
   ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
arch/arm/mach-tegra/reset.c:74:2: note: here
  case 0:
  ^~~~
Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>

arch/arm/mach-tegra/reset.c

@@ -70,7 +70,7 @@ static void __init tegra_cpu_reset_handler_enable(void)
 	switch (err) {
 	case -ENOSYS:
 		tegra_cpu_reset_handler_set(reset_address);
-		/* pass-through */
+		/* fall through */
 	case 0:
 		is_enabled = true;
 		break;