build: build as both static and shared libs

build: build as both static and shared libs

This patch changes the build process to group all .o files for a driver or
library into a static archive first, and then link the .o files together
into a shared library. This eliminates the need for separate static or
shared object builds when packaging, for instance.

The "default_library" configuration option now only affects the apps and
examples, which are either linked against the static or shared library
versions depending on the value of the option.

Signed-off-by: Bruce Richardson <bruce.richardson@intel.com>
Acked-by: Luca Boccassi <bluca@debian.org>