Fix build errors with .c and .cc files being in the libcgpt-cc.a

When I build without this fix, I get errors like this:
  armv7a-cros-linux-gnueabi-strip:....libcgpt-cc.a(CgptManager.cc):
  Unable to recognise the format of file: File format not recognized

The .a file shouldn't have .cc files in it anyway.

The error appears to have been introduced in:
  https://gerrit.chromium.org/gerrit/16433

I'm not sure why it wasn't noticed until now, but perhaps the
new toolchain is just pickier.

BUG=None
TEST=emerge-daisy vboot_reference works
TEST=With future hardfp change, can boot U-Boot compiled with new
toolchain.

Change-Id: I33f15fb38d7e236000845d0a864c1e86469f32c7
Reviewed-on: https://gerrit.chromium.org/gerrit/22476
Tested-by: Doug Anderson <dianders@chromium.org>
Reviewed-by: Mike Frysinger <vapier@chromium.org>
Commit-Ready: Doug Anderson <dianders@chromium.org>
1 file changed