staging: r8188eu: Remove header file include/usb_hal.h

staging: r8188eu: Remove header file include/usb_hal.h

This header only includes one prototype and one define statement. The
new definition is used once, thus it can be removed. The prototype is
moved to a header that is already called by the supplier and the user
of that routine, thus the small header is removed.

Signed-off-by: Larry Finger <Larry.Finger@lwfinger.net>
Link: https://lore.kernel.org/r/20210729170930.23171-5-Larry.Finger@lwfinger.net
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>