Change dynamic PMDA to use quoted include for libpcp.h

Match qa/src pattern of using "libpcp.h" instead of <pcp/libpcp.h>.
The -I../../src flag in GNUmakefile.install now finds the file at
../../src/libpcp.h without needing a pcp/ subdirectory structure.

Author: tallpsmith

qa/pmdas/dynamic/dynamic.c

@@ -8,7 +8,7 @@
 #include <syslog.h>
 #include <errno.h>
 #include <pcp/pmapi.h>
-#include <pcp/libpcp.h>
+#include "libpcp.h"
 #include <pcp/pmda.h>
 #include "domain.h"