kernel: bump 6.12 to 6.12.38

Changelog: https://cdn.kernel.org/pub/linux/kernel/v6.x/ChangeLog-6.12.38
Minor kernel update with a single fix:
-  x86/CPU/AMD: Properly check the TSA microcode

Signed-off-by: Leo Barsky <[email protected]>
Link: https://github.com/openwrt/openwrt/pull/19411
Signed-off-by: Hauke Mehrtens <[email protected]>

target/linux/generic/kernel-6.12

@@ -1,2 +1,2 @@
-LINUX_VERSION-6.12 = .37
-LINUX_KERNEL_HASH-6.12.37 = 936fdfd2405b5e0ac38d4e094b07772610c22cd478f4bb257c9bf929e762ff95
+LINUX_VERSION-6.12 = .38
+LINUX_KERNEL_HASH-6.12.38 = f035fa8d83d59f793c76b23567b130cc42118f10696815fed03c16bb15670fcc