makefile: remove print-chip-variant
makefile: remove print-chip-variant

We ended up deciding on a different design for the location of ISH
firmware in the filesystem (long ago), and the chip variant is no
longer needed in the ebuild. Remove this target.

BUG=b:122371717
BRANCH=none
TEST=buildall

Change-Id: I9d5152537c9f4e86296546b86c98f581534d379f
Signed-off-by: Jack Rosenthal <d3f605bef1867f59845d4ce6e4f83b8dc9e4e0ae@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/ec/+/1742418
Reviewed-by: Raul E Rangel <9a9c998e11a2655b1de9a05eeeef5f710c0dc7ed@chromium.org>

coreboot/chrome-ec,coreboot/chrome-ec,coreboot/chrome-ec,coreboot/chrome-ec,coreboot/chrome-ec,coreboot/chrome-ec