gnu: Use 'cc-for-target' instead of custom implementations.

gnu: Use 'cc-for-target' instead of custom implementations.

* gnu/packages/compression.scm (ecm)[arguments]: In #:make-flags, remove
TARGET binding and use CC-FOR-TARGET instead.
* gnu/packages/linux.scm (powerstat, crda, cachefilesd)[arguments]: Likewise.
* gnu/packages/mail.scm (alpine)[arguments]: Likewise.
* gnu/packages/music.scm (lsp-plugins)[arguments]: Likewise.
* gnu/packages/radio.scm (dump1090)[arguments]: Likewise.
* gnu/packages/suckless.scm (blind, dmenu, spoon, slock, st, surf, sent,
wificurse, sbm, prout, noice, human, fortify-headers, colors, libutf,
scron)[arguments]: Likewise.