Install libQgpsmm_global.h to /usr/include.

The file will be gone completely, but for now ship it to make the header
file usable.

Closes: #636647
Thanks: Lisandro Damián Nicanor Pérez Meyer

debian/libqgpsmm-dev.install

@@ -1,2 +1,3 @@
 debian/tmp/usr/lib/pkgconfig/Qgpsmm.pc
 debian/tmp/usr/lib/libQgpsmm.prl
+libQgpsmm/libQgpsmm_global.h /usr/include