Update Linux to v5.4.2

Change-Id: Idf6911045d9d382da2cfe01b1edff026404ac8fd
diff --git a/arch/mips/pci/ops-bcm63xx.c b/arch/mips/pci/ops-bcm63xx.c
index d02eb9d..925c723 100644
--- a/arch/mips/pci/ops-bcm63xx.c
+++ b/arch/mips/pci/ops-bcm63xx.c
@@ -474,6 +474,7 @@
 		if (PCI_SLOT(devfn) == 0)
 			return bcm_pcie_readl(PCIE_DLSTATUS_REG)
 					& DLSTATUS_PHYLINKUP;
+		/* else, fall through */
 	default:
 		return false;
 	}