Silicon/Intel/Tools: Add .gitignore file to ignore the generated .o/.obj

C tools are compiled first. Their generation files .o/.obj/.d/.pdb should be ignored.

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