*.h: Fix up typos in guarding

Clang complains about this.

Change-Id: I421d6c5daa373d1537e4ac2243438e7f1f6208d1
Signed-off-by: Arthur Heymans <arthur@aheymans.xyz>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/63067
Reviewed-by: Angel Pons <th3fanbus@gmail.com>
Reviewed-by: Elyes Haouas <ehaouas@noos.fr>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

src/soc/intel/xeon_sp/include/soc/itss.h

@@ -1,7 +1,7 @@
 /* SPDX-License-Identifier: GPL-2.0-only */
 
 #ifndef SOC_INTEL_XEON_SP_ITSS_H
-#define SOC_INTEL_XEONS_P_ITSS_H
+#define SOC_INTEL_XEON_SP_ITSS_H
 
 #define ITSS_MAX_IRQ	119
 #define IRQS_PER_IPC	32