crt: Support delay loaded libraries

The C runtime has the configure option --enable-delay-import-libs to
enable the creation of delay loaded libraries, however this option
does not work. Given such libraries can be useful to have for users
it would be helpful to properly support them.

mingw-w64-crt/ChangeLog:

	* Makefile.am (AM_DLLTOOLFLAGS): Properly handle delay loaded library name.

Signed-off-by: TheShermanTanker <tanksherman27@gmail.com>
Signed-off-by: LIU Hao <lh_mouse@126.com>