Remove mmc-hs400-enhanced-strobe from the rk3399-khadas-edge dts to
improve compatibility with a wider range of eMMC chips.

Before (BJTD4R 29.1 GiB):

[    7.001493] mmc2: CQHCI version 5.10
[    7.027971] mmc2: SDHCI controller on fe330000.mmc [fe330000.mmc] using ADMA
.......
[    7.207086] mmc2: mmc_select_hs400es failed, error -110
[    7.207129] mmc2: error -110 whilst initialising MMC card
[    7.308893] mmc2: mmc_select_hs400es failed, error -110
[    7.308921] mmc2: error -110 whilst initialising MMC card
[    7.427524] mmc2: mmc_select_hs400es failed, error -110
[    7.427546] mmc2: error -110 whilst initialising MMC card
[    7.590993] mmc2: mmc_select_hs400es failed, error -110
[    7.591012] mmc2: error -110 whilst initialising MMC card

After:

[    6.960785] mmc2: CQHCI version 5.10
[    6.984672] mmc2: SDHCI controller on fe330000.mmc [fe330000.mmc] using ADMA
[    7.175021] mmc2: Command Queue Engine enabled
[    7.175053] mmc2: new HS400 MMC card at address 0001
[    7.175808] mmcblk2: mmc2:0001 BJTD4R 29.1 GiB
[    7.176033] mmcblk2boot0: mmc2:0001 BJTD4R 4.00 MiB
[    7.176245] mmcblk2boot1: mmc2:0001 BJTD4R 4.00 MiB
[    7.176495] mmcblk2rpmb: mmc2:0001 BJTD4R 4.00 MiB, chardev (242:0)

Fixes: c2aaccee ("arm64: dts: rockchip: Add support for Khadas Edge/Edge-V/Captain boards")
Signed-off-by: Artem Lapkin <art@khadas.com>
Link: https://lore.kernel.org/r/20211115083321.2627461-1-art@khadas.comSigned-off-by: Heiko Stuebner <heiko@sntech.de>