Split LD flags

LDLIBS = libraries name with or without the -l prefix
LDFLAGS = optionnal LD flags

Signed-off-by: Jean-Marie Lemetayer <jeanmarie.lemetayer@gmail.com>
Manage LD flags for all the module types

Signed-off-by: Jean-Marie Lemetayer <jeanmarie.lemetayer@gmail.com>