Fix runpath and library filename

I'm away from home and won't be able to fully test these changes for a few days, but I believe they fix a number of issues with tools and libraries provided by rocm-hipamd.

• d/patches: add 0020-hipcc-remove-rpath-flags.patch Closes: #1021642
• d/rules: trim unnecessary rules
• d/rules: strip RUNPATH from libamdhip64.so
• debian/patches: backport 56b3260 from upstream Closes: #1021643