As vqmmc-supply is an optional Device Tree property, don't skip vccq
reconfiguration when the regulator is not specified. Instead, accept
voltage specified by the voltage-ranges property.
The actual voltage switch is done through a hw register in LS1028A.
Add errata flag for other boards, as they are not supported. Return
not supported error code when switching to 1.8V on affected platforms.
Fixes: b08bf4c3 ("sdhci_fsl_fdt: Skip vccq reconfiguration without regulator")
Co-authored-by: Artur Rojek <email@example.com>