pcengines-apu-firmware: Update to version 4.14.0.4

pcengines-apu-firmware: Update to version 4.14.0.4

- Update from 4.14.0.2 to 4.14.0.4
- Update of rootfile
- Changelog
   v4.14.0.4 Release date: 2021-09-17
    Changed:
        Rebased with official coreboot repository commit d9f5d90
        Enabled EHCI controller by default on apu3-apu6 platforms
        Updated sortbootorder to v4.6.22
    Added:
        Safeguard against setting watchdog timeout too low
    Known issues:
        apuled driver doesn't work in FreeBSD. Check the GPIOs document for workaround.
        Some PCIe cards are not detected on certain OSes and/or in certain mPCIe slots.
         Check the mPCIe modules document for solution/workaround.
        Booting with 2 USB 3.x sticks plugged in apu4 sometimes results in detecting
         only 1 stick
        Certain USB 3.x sticks happen to not appear in boot menu
        Booting Xen is unstable
   v4.14.0.3 Release date: 2021-08-06
    Changed:
        Rebased with official coreboot repository commit c049c80

Signed-off-by: Adolf Belka <adolf.belka@ipfire.org>
Signed-off-by: Arne Fitzenreiter <arne_f@ipfire.org>