Merge tag 'u-boot-stm32-20200324' of https://gitlab.denx.de/u-boot/custodians/u-boot-stm into next

- stm32mp: fix command stboard
- stm32mp: update kernel device tree according the part number
- stm32mp: add 800 MHz profile support = stm32mp15xd and stm32mp15xf
- stm32mp: set cp15 frequency in psci cpu on
- stm32mp: DT alignment with Linux 5.6-rc1
- stm32mp: clk: add SPI5 support and correct CKSELR masks
- stm32mp: ram: fixes on LPDDR2/LPDDR3 support and on tuning
- stm32: i2c: allows for any bus frequency
- sti: timer: livetree and clk API conversion