Internal pull-down for strobe line (GRF_EMMCPHY_CON2[9]) was disabled
by commit 8b5c2b45, which causes I/O error in HS400 mode.

Tested on NanoPC-T4.

Fixes: 8b5c2b45 ("phy: rockchip: set pulldown for strobe line in dts")
Signed-off-by: Jensen Huang <jensenhuang@friendlyarm.com>
Link: https://lore.kernel.org/r/20220928091129.20597-1-jensenhuang@friendlyarm.comSigned-off-by: Heiko Stuebner <heiko@sntech.de>