gnu: make-qmk-firmware: Use AVR target.

* gnu/packages/firmware.scm (qmk)[inputs]: Remove AVR toolchain.
[arguments]: Adjust phase wrapping output.
(make-qmk-firmware/implementation)[arguments]: Add avr as target.

Change-Id: Ibe09f6ef3c555052faf2c5c243303d85675866be
Signed-off-by: Efraim Flashner <efraim@flashner.co.il>

gnu/packages/firmware.scm

@@ -1344,9 +1344,7 @@ corresponding layout." layout))
                 `("PATH" prefix
                   ,(map (compose dirname
                                  (cut search-input-file inputs <>))
-                        '("bin/avr-ar"
-                          "bin/avr-gcc"
-                          "bin/avrdude"
+                        '("bin/avrdude"
                           "bin/awk"
                           "bin/cmp"
                           "bin/dfu-programmer"
@@ -1359,16 +1357,13 @@ corresponding layout." layout))
                           ;; TODO: Remove after git is wrapped with these.
                           "bin/basename"
                           "bin/sed"
-                          "bin/uname")))
-                `("CROSS_C_INCLUDE_PATH" = (,(getenv "CROSS_C_INCLUDE_PATH")))
-                `("CROSS_LIBRARY_PATH" = (,(getenv "CROSS_LIBRARY_PATH")))))))))
+                          "bin/uname")))))))))
     ;; The inputs are not propagated since qmk is to be used strictly as a
     ;; command.
     (inputs
      ;; The 'qmk setup' command advises to use GCC at version 8, and there are
      ;; compilation errors in some firmware otherwise.
-     (list (make-avr-toolchain #:xgcc gcc-8)
-           avrdude
+     (list avrdude
            bash-minimal
            dfu-programmer
            dfu-util
@@ -1441,6 +1436,7 @@ provided."
                   (ice-9 ftw)
                   (ice-9 match)
                   (srfi srfi-26))
+      #:target "avr"
       ;; XXX: Running a test target like "test:$keyboard" doesn't seem to run
       ;; anything and causes the .hex file to be regenerated; leave the tests
       ;; out for now.