[MTD] [NOR] Add support for Eon EN29SL800B[BT] NOR flash chips

This patch add support for non-CFI Eon EN29SL800B[BT] NOR flash chips.
The Eon chips have manufacturer ID in the first bank, therefore this patch
depends on support for flash chips with ID in bank other than 0.

Signed-off-by: Mike Rapoport <mike@compulab.co.il>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>