[MTD] MAPS: Support for BIOS flash chips on Intel ESB2 southbridge

Add MTD map driver for BIOS flash chips connected to the Intel ESB2
southbridge.

[akpm@osdl.org: coding-style fixes, build fix]
Signed-off-by: Ryan Jackson <rjackson@lnxi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>