cbtypes.h: Unify cbtypes.h used in AMD board's code

Remove all the repeated sections of code in cbtypes.h and place it
in a common location. Add include dir in vendor code's Makefile.

Change-Id: Ida92c2a7a88e9520b84b0dcbbf37cd5c9f63f798
Signed-off-by: Vikram Narayanan <vikram186@gmail.com>
Reviewed-on: http://review.coreboot.org/912
Tested-by: build bot (Jenkins)
Reviewed-by: Marc Jones <marcj303@gmail.com>
12 files changed