Revert "genirq: Export affinity setter for modules"

This reverts commit dde45d80 which is
commit 4d80d6ca upstream.

It breaks the Android kernel abi and can be brought back in the future
in an abi-safe way if it is really needed.

Bug: 161946584
Change-Id: I405697b86772dbe473fa4088b135c469bc8c6244
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>