s390: enable DEBUG_FORCE_FUNCTION_ALIGN_64B

Allow to enforce 64 byte function alignment like it is possible for a
couple of other architectures. This may or may not be helpful for
debugging performance problems, as described with the Kconfig option.

Since the kernel works also with 64 byte function alignment there is
no reason for not allowing to enforce this function alignment.
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>

lib/Kconfig.debug

@@ -502,7 +502,7 @@ config SECTION_MISMATCH_WARN_ONLY
 
 config DEBUG_FORCE_FUNCTION_ALIGN_64B
 	bool "Force all function address 64B aligned"
-	depends on EXPERT && (X86_64 || ARM64 || PPC32 || PPC64 || ARC)
+	depends on EXPERT && (X86_64 || ARM64 || PPC32 || PPC64 || ARC || S390)
 	select FUNCTION_ALIGNMENT_64B
 	help
 	  There are cases that a commit from one domain changes the function