pgsql: Add a missing dependency: the "install" target requires "all" to

Log Message:
-----------
Add a missing dependency: the "install" target requires "all" to have
been built before it. Per report from Kris Jurka.

Modified Files:
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pgsql/src/port:
Makefile (r1.20 -> r1.21)
(http://developer.postgresql.org/cvsweb.cgi/pgsql/src/port/Makefile.diff?r1=1.20&r2=1.21)