[meta] Remove unused patch files from the tree
There are some 'dangling' patch files in the tree from past versions of packages that are no longer referenced from their respective APKBUILD
files. It would be prudent to vacuum the tree.
Quasi-related to #836 as it will introduce automated scanning for this, but it'd probably be easy to write a script in some language (shell, Perl, Python, Ruby, whatever) to do a once-over on the tree for tidying purposes.