Reset controller fixes for v4.14

- Remove misleading HSDK v1 suffix, as there is no v2 planned
- Add missing DT binding documentation for HSDK reset driver
- Fix HSDK reset driver dependencies

* tag 'reset-fixes-for-4.14' of git://git.pengutronix.de/git/pza/linux:
  reset: Restrict RESET_HSDK to ARC_SOC_HSDK or COMPILE_TEST
  ARC: reset: remove the misleading v1 suffix all over
  ARC: reset: add missing DT binding documentation for HSDKv1 reset driver
  ARC: reset: Only build on archs that have IOMEM
Signed-off-by: Olof Johansson <olof@lixom.net>