Add Linux 6.1

This change adds support for building a Linux 6.1 Proxmox Edge kernel.

I have decided not to create releases for this major version since Proxmox
has already released an official supported pve-kernel-6.1.
See https://forum.proxmox.com/threads/opt-in-linux-6-1-kernel-for-proxmox-ve-7-x-available.119483
for more information.

debian/patches/pve/0004-kvm-disable-default-dynamic-halt-polling-growth.patch

@@ -13,7 +13,7 @@ Signed-off-by: Thomas Lamprecht <t.lamprecht@proxmox.com>
  1 file changed, 1 insertion(+), 1 deletion(-)
 
 diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
-index c56861ed0e38..3ba11c5e7acd 100644
+index fab4d3790578..adae153354c2 100644
 --- a/virt/kvm/kvm_main.c
 +++ b/virt/kvm/kvm_main.c
 @@ -79,7 +79,7 @@ module_param(halt_poll_ns, uint, 0644);