lang/gcc14-devel: fix build on armv7
Make sure a BOOTSTRAP option is set for armv7.
Also fix plist by including the libitm info file.
Approved by: portmgr (build fix blanket)
MFH: 2025Q1
(cherry picked from commit 00c049a08db5c867eaddfc253b2b8c117d79f0cf)