adb: Expose device usb_handle through libadbd

Fastbootd will reuses adb's functionfs transport
implementation.

Move it to daemon/include as well so it can be accessed
with "adbd/usb.h". Otherwise usb.h will conflict with
other imports.

Test: adb builds and works
Bug: 78793464
Change-Id: If3ba190d5c74b5f3633411f0484195e5a2a34d44