ARM: dts: BCM5301X: Linksys EA9500 add port 5 and port 7

Add ports 5 and 7 which are connected to gmac cores 1 & 2.
These will be disabled for now.

Signed-off-by: Vivek Unune <npcomplete13@gmail.com>
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>