Convert modifier of make variables from :C to :S where strings are fixed.
Adjust wording of comment line in patch.
(Upstream update 3.7.2.1 to 3.7.5)
ChangeLog for 3.7.5
  http://gnuradio.org/redmine/projects/gnuradio/wiki/ChangeLogV3_7_5
ChangeLog for 3.7.2
  http://gnuradio.org/redmine/projects/gnuradio/wiki/ChangeLogV3_7_2

(pkgsrc)
convert cmake command at do-configure: to USE_CMAKE= yes style
(Not all combinations of options are verified yet, sorry).