Add i.MX8ULP EVK basic support, support SD/I2C/ENET/LPUART

Log as below: I would keep some debug info for now, and after we move
to be stable and production launch, we could drop that.

U-Boot SPL 2021.07-rc4-00164-gb800e19a6b (Jun 29 2021 - 10:23:30 +0800)
Normal Boot
upower_init: soc_id=48
upower_init: version:11.11.6
upower_init: start uPower RAM service
user_upwr_rdy_callb: soc=b
user_upwr_rdy_callb: RAM version:12.6
Turn on switches ok
Turn on memories ok
Clear DDR retention ok
Poll for freq_chg_req on SIM register and change to F1 frequency.
Poll for freq_chg_req on SIM register and change to F0 frequency.
Poll for freq_chg_req on SIM register and change to F1 frequency.
Poll for freq_chg_req on SIM register and change to F2 frequency.
Poll for freq_chg_req on SIM register and change to F1 frequency.
Poll for freq_chg_req on SIM register and change to F2 frequency.
complete
De-Skew PLL is locked and ready
WDT:   Not found!
Trying to boot from BOOTROM
image offset 0x8000, pagesize 0x200, ivt offset 0x0
Load image from 0x3a800 by ROM_API
NOTICE:  BL31: v2.4(release):imx_5.10.35_2.0.0_imx8ulp_er-10-gf37e59b94
NOTICE:  BL31: Built : 01:56:58, Jun 29 2021
NOTICE:  upower_init: start uPower RAM service
NOTICE:  user_upwr_rdy_callb: soc=b
NOTICE:  user_upwr_rdy_callb: RAM version:12.6

U-Boot 2021.07-rc4-00164-gb800e19a6b (Jun 29 2021 - 10:23:30 +0800)

CPU:   Freescale i.MX8ULP rev1.0 at 744 MHz
Reset cause: POR
Boot mode: Single boot
Model: FSL i.MX8ULP EVK
DRAM:  2 GiB
MMC:   FSL_SDHC: 0, FSL_SDHC: 2
Loading Environment from MMC... ***
Warning - bad CRC, using default environment

In:    serial@293a0000
Out:   serial@293a0000
Err:   serial@293a0000
Net:
Warning: ethernet@29950000 (eth0) using random MAC address -
96:35:88:62:e0:44
eth0: ethernet@29950000
Hit any key to stop autoboot:  0
Signed-off-by: NPeng Fan <peng.fan@nxp.com>