Merge branch 'master' of https://gitlab.denx.de/u-boot/custodians/u-boot-spi

- spi cs accessing slaves (Bin Meng)
- spi prevent overriding established bus (Marcin Wojtas)
- support speed in spi command (Marek Vasut)
- add W25N01GV spinand (Robert Marko)
- move cadence_qspi to use spi-mem (Vignesh Raghavendra)
- add octal mode (Vignesh Raghavendra)