Release v2.6.0

Erik Sallmann (1):
      Add modules_install target to Makefile

Lino Sanfilippo (6):
      Print a note for not found IO-devices
      In init_gpios() setup RS485 termination GPIO
      Introduce macro for first IO device on the left side
      Set base device RS485 termination depending on topology
      Set termination on RevPi extension modules
      Bump to version 2.6.0

Thomas Böhler (5):
      ci: fix regex for linux headers version
      switch to use hrtimer_setup{,_on_stack}
      editorconfig: add .editorconfig
      piControlMain: Simplify send_internal_gate_msg()
      piControlMain: reword firmware update messages