ramips: fix Ubiquiti EdgeRouter X's MAC address for gmac1
This fixes:
[ 0.586649] OF: /ethernet@1e100000/mac@1: #nvmem-cell-cells = 1 found 0
Fixes: 28b6224104cc ("ramips: use fixed layout cell "mac-base" for Ubiquiti EdgeRouter X")
Signed-off-by: Rafał Miłecki <[email protected]>