The node name preferred by mmc-controller.yaml binding spec is "mmc":
berlin2-sony-nsz-gs7.dt.yaml: sdhci@ab0000: $nodename:0:
'sdhci@ab0000' does not match '^mmc(@.*)?$'
berlin2-sony-nsz-gs7.dt.yaml: sdhci@ab0800: $nodename:0:
'sdhci@ab0800' does not match '^mmc(@.*)?$'
berlin2-sony-nsz-gs7.dt.yaml: sdhci@ab1000: $nodename:0:
'sdhci@ab1000' does not match '^mmc(@.*)?$'
berlin2cd-google-chromecast.dt.yaml: sdhci@ab0000: $nodename:0:
'sdhci@ab0000' does not match '^mmc(@.*)?$'
berlin2cd-valve-steamlink.dt.yaml: sdhci@ab0000: $nodename:0:
'sdhci@ab0000' does not match '^mmc(@.*)?$'
berlin2q-marvell-dmp.dt.yaml: sdhci@ab0000: $nodename:0:
'sdhci@ab0000' does not match '^mmc(@.*)?$'
berlin2q-marvell-dmp.dt.yaml: sdhci@ab0800: $nodename:0:
'sdhci@ab0800' does not match '^mmc(@.*)?$'
berlin2q-marvell-dmp.dt.yaml: sdhci@ab1000: $nodename:0:
'sdhci@ab1000' does not match '^mmc(@.*)?$'