tile: Fix vDSO compilation issue with allyesconfig

make allyesconfig give the following build error on tile:
 tilegx-linux-gcc: error: arch/tile/kernel/vdso/vgettimeofday32.o: No such file or directory
 tilegx-linux-objcopy: 'arch/tile/kernel/vdso/vdso32.so.dbg': No such file or directory

In case with CONFIG_MODVERSIONS, cmd_cc_o_c generate .tmp_<file>.o from
<file>.c only. Fix it by execute rule_cc_o_c instead.

Reported-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Kerry Sheh <ksheh@tilera.com>
Signed-off-by: Chris Metcalf <cmetcalf@tilera.com>