power: Remove libbase_ver override in gyp file.

CL:194476 modified platform2 to build against libchrome-242728. The
libbase_ver override in the gyp file is no longer needed.

BUG=chromium:361748
TEST=`FEATURES=test emerge-$BOARD platform2`
TEST=Verify that powerd is linked against libchrome-242728.

Change-Id: I1064666a907242ea16d84a5189e29adb2696f2d4
Reviewed-on: https://chromium-review.googlesource.com/196723
Commit-Queue: Ben Chan <benchan@chromium.org>
Tested-by: Ben Chan <benchan@chromium.org>
Reviewed-by: Mike Frysinger <vapier@chromium.org>
1 file changed