fiptool: remove unneeded -I. include path

All local headers in tools/fiptool are included by #include "..."
notation instead of #include <...>, so there is no need to add the
local directory to to the header search path.
Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>

tools/fiptool/Makefile

@@ -27,7 +27,7 @@ else
   Q :=
 endif
 
-INCLUDE_PATHS := -I. -I../../include/tools_share
+INCLUDE_PATHS := -I../../include/tools_share
 
 HOSTCC ?= gcc