USB: Use EHCI control transfer pid macros instead of constant values.

Macros with good names offer better readability. Besides, also move
the definition to ehci.h.

Signed-off-by: Dingyan Li <18500469033@163.com>
Reviewed-by: Alan Stern <stern@rowland.harvard.edu>
Link: https://lore.kernel.org/r/20240309033709.14604-1-18500469033@163.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>