kernel: bump 5.4 to 5.4.139

All patches automatically rebased.

Build system: x86_64
Build-tested: ipq806x/R7800
Run-tested: ipq806x/R7800

No dmesg regressions, everything functional

Signed-off-by: John Audia <graysky@archlinux.us>

target/linux/realtek/patches-5.4/703-include-linux-add-phy-ops-for-rtl838x.patch

@@ -1,6 +1,6 @@
 --- a/include/linux/phy.h
 +++ b/include/linux/phy.h
-@@ -644,6 +644,10 @@ struct phy_driver {
+@@ -645,6 +645,10 @@ struct phy_driver {
  			    struct ethtool_tunable *tuna,
  			    const void *data);
  	int (*set_loopback)(struct phy_device *dev, bool enable);