kernel: bump 5.4 to 5.4.105

kernel: bump 5.4 to 5.4.105

Ran update_kernel.sh in a fresh clone without any existing toolchains.

Removed upstreamed generic-backports:
  830-v5.12-0001-net-usb-qmi_wwan-support-ZTE-P685M-modem.patch
  831-v5.9-usbip-tools-fix-build-error-for-multiple-definition.patch
  755-v5.8-net-dsa-add-GRO-support-via-gro_cells.patch

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

No dmesg regressions, everything functional

Signed-off-by: John Audia <[email protected]>
Tested-by: Curtis Deptuck <[email protected]> [x86/64]
[squash patches]
Signed-off-by: Adrian Schmutzler <[email protected]>