Merge tag 'u-boot-stm32-20190412' of https://github.com/patrickdelaunay/u-boot

stm32 patches for v2019.07-rc1
- Add trusted boot with TF-A for stm32mp1
- stm32mp1 dts files sync'ed with Linux version
- add STM32MP1 Discovery boards (DK1 and DK2)
- add STMFX gpio expander driver
- misc improvement for stm3mp1 supports
- rename stpmu1 to stpmic1 (official name)
- stm32_qspi: move to exec_op (spi nor driver for stm32 mpu and mcu)
- add STM32 FMC2 NAND flash controller driver