Documentation: zh: remove references to IrDA

These lines blame back to their first appearance which cites linux-2.6,
and IrDA was finally fully removed in 4.17 with commit d64c2a76
("staging: irda: remove the irda network stack and drivers")

Signed-off-by: Ahelenia Ziemiańska <nabijaczleweli@nabijaczleweli.xyz>
Link: https://lore.kernel.org/r/d07ce5b1bc173fd02b7e5b708beb81b9432745f8.1663280877.git.nabijaczleweli@nabijaczleweli.xyz


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>