Upgrade ASK kernel base to Linux 6.18.30

Move the custom ASK/NXP kernel build from lf-6.18.2-1.0.0 toward
the upstream stable 6.18.y baseline, currently 6.18.30.

This pulls in upstream stable fixes, including the BPF verifier fix needed
by Cilium. The previous 6.18.2-based kernel triggered:

  verifier bug: REG INVARIANTS VIOLATION (false_reg1)
  reg_bounds_sanity_check()
  bpf_prog_load()
  cilium-agent

The issue is no longer reproduced on 6.18.30 after fresh boot:
Cilium 1.19.2 reports healthy, BPF datapath is active, all controllers are
healthy, cluster health is reachable, and dmesg no longer shows the verifier
warning.

Refresh affected ASK upstream patch splits:
- add bridge br_input patch
- refresh xfrm policy/state patches
- update package/kernel build inputs for 6.18.30

build.env

@@ -6,6 +6,15 @@ TAG=dev
 # NXP's Linux Factory
 LINUX_FACTORY=6.18.2-1.0.0
 NXP_VERSION=lf-$(LINUX_FACTORY)
+NXP_KERNEL_VERSION=6.18.30-1.0.0-dev
+
+# This kernel applies upstream fixes
+# If you want the original, use:
+#    https://github.com/nxp-qoriq/linux/archive/refs/tags/lf-${NXP_KERNEL_VERSION}.tar.gz
+# and change NXP_KERNEL_VERSION to match LINUX_FACTORY
+# However you may have to fix the failed patches in patches/ask/upstream/kernel/
+NXP_KERNEL_URL=https://github.com/tgckpg/linux-layerscape-stable/archive/refs/tags/lf-${NXP_KERNEL_VERSION}.tar.gz
+
 FMLIB_VERSION=lf-$(LINUX_FACTORY)
 FMC_VERSION=lf-$(LINUX_FACTORY)
 DPDK_VERSION=lf-$(LINUX_FACTORY)