REF: https://bugzilla.tianocore.org/show_bug.cgi?id=2203
This patch is going to fix a regression issue that
build breaks when the custom makefile exist.
Cc: Liming Gao <liming.gao@intel.com>
Cc: Steven Shi <steven.shi@intel.com>
Signed-off-by: Bob Feng <bob.c.feng@intel.com>
Reviewed-by: Liming Gao <liming.gao@intel.com>
4747b92cab