staging: gdm724x: Fix warning of prefer ether_addr_copy.

This patch fixes the following checkpatch.pl warnings:
WARNING: "Prefer ether_addr_copy() over memcpy() if the Ethernet
addresses are __aligned(2)" in file gdm_lte.c
Pahole shows that the addresses are aligned.

Signed-off-by: Dilek Uzulmez <dilekuzulmez@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>