linux-aspeed: Move to v5.15.26 stable release

This includes security and bug fixes from the 5.15.25 through to
5.15.26 stable releases.

Notably it includes a fix for CVE-2022-0847, the "Dirty Pipe"
vulnerability.

Change-Id: I8fe3aabf8cf0bd6cf03f437a548b58f942c22b13
Signed-off-by: Joel Stanley <joel@jms.id.au>
diff --git a/meta-aspeed/recipes-kernel/linux/linux-aspeed_git.bb b/meta-aspeed/recipes-kernel/linux/linux-aspeed_git.bb
index c0190e5..a8beec27 100644
--- a/meta-aspeed/recipes-kernel/linux/linux-aspeed_git.bb
+++ b/meta-aspeed/recipes-kernel/linux/linux-aspeed_git.bb
@@ -1,6 +1,6 @@
 KBRANCH ?= "dev-5.15"
-LINUX_VERSION ?= "5.15.24"
+LINUX_VERSION ?= "5.15.26"
 
-SRCREV="de0980ea2d5360bd1d7472e62231a03c108f20c2"
+SRCREV="c4c3fba61580d267568c5c9cf10c928a41ba38a4"
 
 require linux-aspeed.inc