package/pkg-generic: make libtool .la files compatible with per-package directories

package/pkg-generic: make libtool .la files compatible with per-package directories

Libtool .la files unfortunately contain a number of absolute paths,
which now refer to per-package directories. Due to this, when building
package A, .la files may contain absolute paths referring to
directories in package B per-package sysroot. This causes some -L
flags referring to other sysroot from being added, which doesn't work
as the linker no longer realizes that such paths are within its
sysroot.

To fix this, we introduce a replacement step of .la files in the
configure step, to make sure all paths refer to this package
per-package directory.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>