Some codec nodes of the s400 sound card are numbered with the pattern
codec@XX. This pattern should be used only if there is a reg property in
the node which is not case here. Change this to something acceptable.

This change is only to better comply with the DT spec. No functional
changes expected.

Fixes: 6f59dc1a ("arm64: dts: meson-axg: s400: add sound card")
Signed-off-by: Jerome Brunet <jbrunet@baylibre.com>
Signed-off-by: Kevin Hilman <khilman@baylibre.com>
Link: https://lore.kernel.org/r/20200224150812.263980-3-jbrunet@baylibre.com