ila: Remove unnecessary file net/ila.h

Commit 642c2c95 ("ila: xlat changes") removed ila_xlat_outgoing()
and ila_xlat_incoming() functions, then this file became unnecessary.

Signed-off-by: Yue Haibing <yuehaibing@huawei.com>
Reviewed-by: Larysa Zaremba <larysa.zaremba@intel.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Link: https://lore.kernel.org/r/20230801143129.40652-1-yuehaibing@huawei.com


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