dns/dhisd: update to 5.5

• while here, adopt the port;
• files/patch-Makefile; use CC=${CC} for clang and GCC compatibility; use PREFIX instead of hardcoding "/usr/local"; better use WFLAGS+= (with a plus).
• also updated 'pkg-descr' with a longer description about the port.

PR: 230990
Submitted by: egypcio
Approved by: rene (mentor)