Merge branch 'next'

Pull in changes that have been pending in our 'next' branch.  This
includes:
- A large number of CI improvements including moving to gcc-9.2 for all
  platforms.
- amlogic, xilinx, stm32, TI SoC updates
- USB and i2c subsystem updtaes
- Re-sync Kbuild/etc logic with v4.19 of the Linux kernel.
- RSA key handling improvements