Makefile.inc: Add math macros

Add macros to standardize math done in the Makefiles in a posix
compliant manner.

int-multiply takes an arbitrary list of values to multiply, the same as
the int-addition macro.

The other macros only work on two values at a time.

Change-Id: I3b754b9bcde26f33edc4f945d5af3d5444f383c7
Signed-off-by: Martin Roth <gaumless@gmail.com>
Reviewed-on: http://review.coreboot.org/10874
Tested-by: build bot (Jenkins)
Reviewed-by: Patrick Georgi <pgeorgi@google.com>

0 files changed, 0 insertions, 0 deletions