ide: Fix fall-through warnings for Clang

In preparation to enable -Wimplicit-fallthrough for Clang, fix a warning
by explicitly adding a break statement instead of letting the code fall
through to the next case.

Link: KSPP#115
Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>

Author: GustavoARSilva

drivers/ide/siimage.c

@@ -493,6 +493,7 @@ static int init_chipset_siimage(struct pci_dev *dev)
 	case 0x30:
 		/* Clocking is disabled, attempt to force 133MHz clocking. */
 		sil_iowrite8(dev, tmp & ~0x20, scsc_addr);
+		break;
 	case 0x10:
 		/* On 133Mhz clocking. */
 		break;