mk: move PMD libraries linking to applications

mk: move PMD libraries linking to applications

Some PMDs provide device specific APIs. Bond and xenvirt are existing
samples for this.

And since these are PMD libraries, there are two options on how to link
them for shared library build:

1- They can be linked to all applications by default, using common
rte.app.mk file.

2- They can be explicitly linked to applications that use device
specific API.

Currently option one is in use, this patch switches to the option two.

Moves library linking to the Makefile of application Makefile that uses
device specific API.

This prevent these PMD libraries to be a dependency to applications
that don't use these device specific APIs.

Signed-off-by: Ferruh Yigit <ferruh.yigit@intel.com>