ARM: dts: berlin*: Fix up the SDHCI node names

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: $nodename:0:
      'sdhci@ab1000' does not match '^mmc(@.*)?$'

Signed-off-by: Lubomir Rintel <lkundrak@v3.sk>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Arnd Bergmann <arnd@arndb.de>