board/xilinx: add hash for Linux 6.6.70

This patch adds the hash for Linux version 6.6.70 for Xilinx boards.

Signed-off-by: Neal Frager <neal.frager@amd.com>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

board/xilinx/patches/linux/linux.hash

@@ -1,2 +1,3 @@
 # Locally calculated
 sha256  f59c7d260794d73ee519ba2579ef41aa8ac4985ac5af9461f94fa314969acd2e  xlnx_rebase_v6.6_LTS_merge_6.6.60.tar.gz
+sha256  b726226e8784d92049190f19768d393eccf3ad111c7a2e685bb29cfa1bdf1f70  xlnx_rebase_v6.6_LTS_merge_6.6.70.tar.gz