arm64: dts: broadcom: Fix sata nodename

After converting ahci-platform txt binding to yaml nodename is reported
as not matching the standard:

arch/arm64/boot/dts/broadcom/northstar2/ns2-svk.dt.yaml:
ahci@663f2000: $nodename:0: 'ahci@663f2000' does not match '^sata(@.*)?$'

Fix it to match binding.

Fixes: ac9aae00 ("arm64: dts: Add SATA3 AHCI and SATA3 PHY DT nodes for NS2")
Signed-off-by: Frank Wunderlich <frank-w@public-files.de>
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>