awk: use awkgram.tab.h consistently

yacc makes awkgram.h. However, one true awk includes awkgram.tab.h, so
we link to for the builds. Make sure that we consistently link to it.
Also, restore the awkgram.tab.h dependency to maketab. It should not
have been deleted, despite apparently making meta build on stable/12
work. The important missing arc was proctab.c's dependence on
awkgram.tab.h.

MFC After: 1 day (build breakage)
Fixes: c50c8502cb629571f35089690d6e9a9bc4d60813
Sponsored by: Netflix