Merge tag 'arm-soc/for-4.21/soc' of https://github.com/Broadcom/stblinux into next/soc

This pull request contains Broadcom ARM-based SoCs machine files updates
for 4.21, please pull the following:

- Stefan switches relevant BCM283x files under arch/arm/mach-bcm to the
  SPDX license identifiers

- Justin adds an entry in the Broadcom STB debug LL stub for 7255

- Florian enables reset controller support for BCM63xx SoCs

* tag 'arm-soc/for-4.21/soc' of https://github.com/Broadcom/stblinux:
  ARM: mach-bcm: Switch bcm2835 and platsmp to SPDX identifier
  ARM: BCM63XX: Enable reset controller support
  ARM: brcmstb: Add entry for 7255

Signed-off-by: Olof Johansson <olof@lixom.net>