libv4l: Make library subdir name configurable

libv4l: Make library subdir name configurable

From: Gregor Jasny <gjasny@googlemail.com>

While studying the Debian library package name, I noticed that private

So /usr/lib/libv4l should become /usr/lib/libv4l0. As this would break
existing scripts, I suggest to start versioning with the next soname bump.

The line in the makefiles will then read:

ifeq ($(LIBSUBDIR),)
LIBSUBDIR = libv4l$(LIB_RELEASE)
endif

Unfortunately, the private subdirs in Debian must be named after the library
package, which would be libv4l-0. Therefore I need to configure the
LIBSUBDIR at compile time.

Priority: normal

Signed-off-by: Gregor Jasny <gjasny@googlemail.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>