MLK-22851-3 imx8mq: Enable eMMC HS400 and SD UHS mode on EVK

MLK-22851-3 imx8mq: Enable eMMC HS400 and SD UHS mode on EVK

iMX8MQ EVK board has a eMMC5.0 chip and supports SD3.0, so enable the UHS
and HS400 configs to enhance the eMMC/SD access.

The change also needs to set usdhc clock to 400Mhz, and add the off-on-delay-us
to SD reset pin, otherwise some SD cards will fail to select UHS mode in
re-initialization.

Signed-off-by: Ye Li <ye.li@nxp.com>
(cherry picked from commit 57e1bc5f634be231b2bfd10cf0cbbff86dadd2e1)
(cherry picked from commit ded7f2aa2354ef9f40a60bf333902437bf33a887)