mmc: sdhci-esdhc-imx: Propagate ESDHC_FLAG_HS400* only on 8bit bus

The core issues the warning "drop HS400 support since no 8-bit bus" when
one of the ESDHC_FLAG_HS400* flags is set on a non 8bit capable host. To
avoid this warning set these flags only on hosts that actually can do
8bit, i.e. have bus-width = <8> set in the device tree.

Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Reviewed-by: Haibo Chen <haibo.chen@nxp.com>
Fixes: 029e2476

 ("mmc: sdhci-esdhc-imx: add HS400_ES support for i.MX8QXP")
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20221013093248.2220802-1-s.hauer@pengutronix.de
Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org>