libudev-zero: backport hwdb USB ID lookup from upstream master

libudev-zero: backport hwdb USB ID lookup from upstream master

Replace the four stub udev_hwdb_*() functions with a working
implementation that looks up vendor and product names from
/usr/share/hwdata/usb.ids, so callers using the standard libudev
hwdb API benefit without needing package-specific patches.

The patch is a clean backport of upstream commit 2bebebc9e0444
("udev: implement hwdb USB ID lookup from usb.ids (#80)") merged
to illiliti/libudev-zero master on 2026-05-19, post-1.0.3. Drop
when the package is bumped to the next libudev-zero release.

Upstream now defaults USB_IDS_PATH to ${SHAREDIR}/hwdata/usb.ids
with SHAREDIR=${PREFIX}/share, so the explicit
USB_IDS_PATH=/usr/share/hwdata/usb.ids in MAKE_FLAGS is no longer
needed and is dropped.

Fixes: https://github.com/openwrt/packages/issues/29386
Signed-off-by: Alexandru Ardelean <redacted>