net: usb: Convert tasklet API to new bottom half workqueue mechanism

Migrate tasklet APIs to the new bottom half workqueue mechanism. It
replaces all occurrences of tasklet usage with the appropriate workqueue
APIs throughout the usbnet driver. This transition ensures compatibility
with the latest design and enhances performance.

Signed-off-by: Jun Miao <jun.miao@intel.com>
Link: https://patch.msgid.link/20250618173923.950510-1-jun.miao@intel.com


Signed-off-by: Jakub Kicinski <kuba@kernel.org>