[MTD] Remove Momenco Ocelot NOR flash support

This patch has removed Momenco Ocelot support from MTD.
Ocelot support has already removed.

Signed-off-by: Yoichi Yuasa <yoichi_yuasa@tripeaks.co.jp>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>