Merge changes from topic "arm_fpga_auto" into integration

* changes:
  feat(arm_fpga): write UART baud base clock frequency into DTB
  feat(arm_fpga): query PL011 to learn system frequency
  refactor(arm_fpga): move command line code into separate function
  fix(fdt): avoid output on missing DT property
  feat(arm_fpga): add ITS autodetection
  feat(arm_fpga): determine GICR base by probing
  feat(gicv3): introduce GIC component identification
  feat(libfdt): also allow changing base address
  fix(arm_fpga): avoid re-linking from executable ELF file