bayleybay_fsp: Add bakersport board variant

The Bakersport board is a variant of the Bayley Bay mainboard that uses
one ECC DIMM instead of two non-ECC dimms.

This commit uses the Bayley Bay mainboard directory and modifies the
required pieces to add the Bakersport board variant.  It disables the
second DIMM, points to an ECC version of the FSP, and sets the board
name to be Bakersport instead of Bayley Bay.

All of the code is still contained in the bayleybay_fsp directory.  It
seems like duplicating the whole directory for the one line of code
that's actually different between the two platforms.

Change-Id: Ia31e9ee927a6810a01a1ae143fcb00cfb7d8a7aa
Signed-off-by: Martin Roth <martin.roth@se-eng.com>
Reviewed-on: http://review.coreboot.org/5983
Tested-by: build bot (Jenkins)
Reviewed-by: Marc Jones <marc.jones@se-eng.com>