gen_settings.pl: Pass in new commandline argument

This is the first commit in a series to solve the problem
of needing to adjust an MRW attribute's value before writing
it back out to the settings override value.

This will be done by allowing mathematical expressions to
be present in the input file, and evaluating them to get
a final result that will get written out.  These expressions
can also use variables whose names and values are passed in
from the command line.

This commit adds the ability to pass in the optional variables
and values from the command line with the -v argument, like:
  -v "VAR1=VAL1 VAR2=VAL2"

Change-Id: I3baf47b38d6da25c5abdaae175ddfc6e97176927
Signed-off-by: Matt Spinler <spinler@us.ibm.com>
1 file changed