Silicon/Tools: Replace white spaces with tabs in GNUmakefile

The tools can't be complied successfully because of the white spaces
in GNUmakefile. So replace them with tabs.

Cc: Bob Feng <bob.c.feng@intel.com>
Cc: Liming Gao <liming.gao@intel.com>
Signed-off-by: Shenglei Zhang <shenglei.zhang@intel.com>
Reviewed-by: Liming Gao <liming.gao@intel.com>