[MTD] cfi_cmdset_0002.c: Add Macronix CFI V1.0 TopBottom detection

This patch adds TopBottom detection for most Macronix chips with CFI V1.0.

The main purpose of this patch is to add detection of the MX29LV400C B
used on the LaCie Ethernet Disk mini V2 NAS.

It detects the following parts correctly:-
MX28F640C3B T
MX29LV002C  B
MX29LV002NC B
MX29LV004C  T
MX29LV400C  T/B
MX29LV800C  T/B
MX29LV160C  T/B
MX29SL800C  T/B
MX29SL802C  T/B

It detects the following uniform part as bottom but it should work
correctly:-
MX29LV040C

For T parts it causes the erase block table to be reversed correctly.
For other parts it avoids the bogus "Assuming top" message.

It does not detect the following correctly:-
MX28F640C3B B
MX29LV002C  T
MX29LV002NC T
MX29LV004C  B
MX29SL400C  T/B
MX29SL402C  T/B

If desired I could supply a more complicated patch to handle these as
well.

Only the MX29LV400C B has been physically tested; others were checked
against their data sheets.

Signed-off-by: Christopher Moore <moore@free.fr>
Signed-off-by: David Woodhouse <David.Woodhouse@intel.com>