sdhci_fsl_fdt(4): Actually use modified SDHCI capabilities

SDHCI_QUIRK_MISSING_CAPS needs to be set unconditionally so sdhci(4)
adheres to the slot caps and caps2 set by sdhci_fsl_fdt(4). However,
so far this bug didn't have an impact as the front-end only filters
SDHCI_CAN_DO_SUSPEND, which in turn isn't used, yet.