mk: fix dependency on toolchain libraries

mk: fix dependency on toolchain libraries

The -l options specifying libraries to link with are in LDLIBS.
But it can happen to have some libraries in other variables.
In case of a low level dependency specified in some environments
via EXTRA_LDFLAGS, there can be an unresolved issue due to a
wrong linking order. Indeed the libraries must be specified from
the higher level (dependency consumers) to the lower level (dependencies).

It is fixed by moving LDLIBS before LDFLAGS variables in the link
command line.

Signed-off-by: Thomas Monjalon <thomas.monjalon@6wind.com>
Tested-by: Raslan Darawsheh <rasland@mellanox.com>