targetPlatform is the platform the current package's programs will
produce binaries for — only relevant for compilers and
similar. hostPlatform is the platform the current package's programs
will run on.
The incorrect use of targetPlatform meant that anything that tried to
link to it (like cryptsetup) would fail to build when it was used as a
native build input for a cross-compiled Musl derivation.
Fixes: 2cc29125a7 ("lvm2: package 2.02.x for musl")