ARM: dts: rockchip: rk3xxx: fix emac node

In the combined DT of rk3066a/rk3188 the emac node uses as place holder
the compatible string "snps,arc-emac". The last real user nSIM_700
of the "snps,arc-emac" compatible string in a driver was removed in 2019.
Rockchip emac nodes don't make use of this common fall back string.
In order to removed unused driver code replace this string with
"rockchip,rk3066-emac".
As we are there remove the blank lines and sort.

Signed-off-by: Johan Jonker <jbx6244@gmail.com>
Reviewed-by: Heiko Stuebner <heiko@sntech.de>
Signed-off-by: David S. Miller <davem@davemloft.net>