Build one nand-part program to handle both A10 and A20 mbr header formats.
Changed -f option to take an "a10" or "a20" argument to specify which mbr
format to force.
Signed-off-by: Patrick Wood <patrickhwood@gmail.com>
A20 boot1 checks the MBR magic string but not the version, but let's
check it anyway (can always force now with the -f option if the version
isn't 0x200 on the system)
allow setting of partition 1 size/offset
if -f option is used, force writing of MBR header, even if CRC or
header magic/version are incorrect (for recovery only)
