powerpc/pasemi: Fix fall-through warning for Clang

Fix the following fallthrough warning:

arch/powerpc/platforms/pasemi/idle.c:45:2: warning: unannotated fall-through between switch labels [-Wimplicit-fallthrough]
Reported-by: kernel test robot <lkp@intel.com>
Link: https://lore.kernel.org/lkml/60efbf18.d9n6eXv275OJcc7T%25lkp@intel.com/Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>

arch/powerpc/platforms/pasemi/idle.c

@@ -42,6 +42,7 @@ static int pasemi_system_reset_exception(struct pt_regs *regs)
 	switch (regs->msr & SRR1_WAKEMASK) {
 	case SRR1_WAKEDEC:
 		set_dec(1);
+		break;
 	case SRR1_WAKEEE:
 		/*
 		 * Handle these when interrupts get re-enabled and we take