linux-aspeed: Disable SLUB_DEBUG

SLUB_DEBUG increases code size and has no known users in production BMC
images. It was likely implicitly enabled when we switched from SLAB to
SLUB in commit 271bf3dce908 ("meta-aspeed: Enable hardened allocator
feature").

aspeed_g5_defconfig (v5.15):

 Total: Before=11329249, After=11309638, chg -0.17%

aspeed_g5_defconfig (v6.0):

 Total: Before=11003344, After=10949112, chg -0.49%

Built with arm-linux-gnueabihf-gcc (Debian 12.2.0-3).

A saving of 19KB for the current kernel, and 54KB for the future kernel
version.

Change-Id: I446d6e8b6e9f4b717de9c3ee06e0b822e5cde75f
Signed-off-by: Joel Stanley <joel@jms.id.au>
diff --git a/meta-aspeed/recipes-kernel/linux/linux-aspeed/aspeed-g6/defconfig b/meta-aspeed/recipes-kernel/linux/linux-aspeed/aspeed-g6/defconfig
index e838299..e12192c 100644
--- a/meta-aspeed/recipes-kernel/linux/linux-aspeed/aspeed-g6/defconfig
+++ b/meta-aspeed/recipes-kernel/linux/linux-aspeed/aspeed-g6/defconfig
@@ -283,6 +283,7 @@
 CONFIG_GDB_SCRIPTS=y
 CONFIG_STRIP_ASM_SYMS=y
 CONFIG_DEBUG_FS=y
+# CONFIG_SLUB_DEBUG is not set
 CONFIG_DEBUG_WX=y
 CONFIG_SCHED_STACK_END_CHECK=y
 CONFIG_PANIC_ON_OOPS=y