vell: cleanup: Remove unused PPC define
vell: cleanup: Remove unused PPC define

BUG=b:211791444
BRANCH=none
TEST=make buildall

Signed-off-by: Devin Lu <052fe648504800b810f29702ef4f3db83fad68bf@quantatw.com>
Change-Id: I4db66d4815a03f0482462fadbc66e14baba675d5
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/ec/+/3596384
Reviewed-by: Boris Mittelberg <46897f4fb5cad4b1d5146ad1fd460d7f4825bbf7@google.com>

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