ARM: shmobile: marzen: add USB EHCI driver support

This patch supports CN21/CN22 USB 2.0 (port 0/1/2),
and enable USB momery on defconfig

Signed-off-by: Kuninori Morimoto <kuninori.morimoto.gx@renesas.com>
Signed-off-by: Simon Horman <horms@verge.net.au>