i.MX fixes for 5.5:
- Add missing jedec,spi-nor compatible for imx6ul-14x14-evk board,
so that SPI NOR device can be probed.
- Fix power button of E60K02 board by removing LDORTC2 regulator.
- A couple of fixes on serial number support of i.MX6ULL/ULZ SoCs to
remove the boot regression caused by 8267ff89b713 ("ARM: imx: Add
serial number support for i.MX6/7 SoCs").
- A couple of fixes on LS1028A SoC TMU regarding to calibration data
and reboot register configuration.
- Fix a regression seen on imx6ul-evk board by marking always-on for
the regulator that is shared by many peripherals.
- Explicitly restore CONFIG_DEBUG_FS in imx_v6_v7_defconfig.