um: gitignore: Add kernel/capflags.c

um: gitignore: Add kernel/capflags.c

BugLink: https://bugs.launchpad.net/bugs/1959376
commit 4b86366fdfbedec42f8f7ee037775f2839921d34 upstream.

This file is generated, we should ignore it.

Fixes: d8fb32f4790f ("um: Add support for host CPU flags and alignment")
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Acked-By: anton.ivanov@cambridgegreys.com
Signed-off-by: Richard Weinberger <richard@nod.at>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Paolo Pisati <paolo.pisati@canonical.com>