regen_makefile.sh: files/flags in separate lines

Make all regen_makefile.sh more readable and diff friendly by moving
each entry in FILES and CPPFLAGS_TTCN3 into separate lines. Order
entries alphabetically.

Related: OS#5252
Change-Id: I6b6866eb9f6ec6232e4ae434517457a4c8c1c050
29 files changed