net: fsl: expands dependencies of NET_VENDOR_FREESCALE

Freescale hosts some ARMv8 based SoCs, and a generic convention
ARCH_LAYERSCAPE is used to cover such SoCs. Adding ARCH_LAYERSCAPE
to dependencies of NET_VENDOR_FREESCALE to support networking on those
SoCs.

The ARCH_LAYERSCAPE is introduced by:
commit: 53a5fde0

 arm64: Use generic Layerscape SoC family naming

Signed-off-by: Shaohui Xie <Shaohui.Xie@freescale.com>
Signed-off-by: David S. Miller <davem@davemloft.net>