Merge tag 'for-v2019.10' of https://gitlab.denx.de/u-boot/custodians/u-boot-i2c

i2c bugfixes for 2019.10
- misc: i2c_eeprom: verify that the chip is functional at probe()
- i2c: mxc_i2c: Remove i2c_idle_bus from probe
- i2c-mux-gpio: Fix GPIO request flag issue