arm64: dts: meson-g12b: fix N2/VIM3 audio card model names

This is largely cosmetic, but Odroid N2 and Khadas VIM3 are G12B devices so
correct the card model names to reflect this.

Fixes: aa7d5873 ("arm64: dts: meson-g12b-odroid-n2: add sound card")
Fixes: c6d29c66 ("arm64: dts: meson-g12b-khadas-vim3: add initial device-tree")
Signed-off-by: Christian Hewitt <christianshewitt@gmail.com>
[khilman: fix whitespace in commit log trailers]
Signed-off-by: Kevin Hilman <khilman@baylibre.com>
Link: https://lore.kernel.org/r/1583135051-95529-1-git-send-email-christianshewitt@gmail.com