pcengines-apu-firmware: Update to version 4.16.0.3

pcengines-apu-firmware: Update to version 4.16.0.3

- Update from 4.15.0.1 to 4.16.0.3
- Update of rootfile
- Changelog
   v4.16.0.3 - Release date: 2022-04-21
      Rebased with official coreboot repository commit 2c4b426557
      See: https://github.com/pcengines/coreboot/compare/v4.16.0.2...v4.16.0.3
   v4.16.0.2 - Release date: 2022-03-29
      Rebased with official coreboot repository commit 66f99f7fa7
      See: https://github.com/pcengines/coreboot/compare/v4.16.0.1...v4.16.0.2
   v4.16.0.1 - Release date: 2022-03-08
      Rebased with official coreboot repository commit b4ba289fa5
      Disabled loglevel prefixes introduced in coreboot 4.16
      Disabled ANSI escape sequences introduced in coreboot 4.16
      Fixed AMD PSP CCP as entropy source
   v4.15.0.3 - Release date: 2022-02-16
      Rebased with official coreboot repository commit 36425312ee
      Added checking hardware matrix before regression tests
      Fixed the hard disk not visible in the Seabios Boot Menu
   v4.15.0.2 - Release date: 2022-01-11
      rebased with official coreboot repository commit 3990da0b
      disabled SMM
      enabled parallel AP initialization for apu2-6 for faster boot time

Signed-off-by: Jon Murphy <jon.murphy@ipfire.org>
Reviewed-by: Peter Müller <peter.mueller@ipfire.org>