s390/kbuild: enable modversions for symbols exported from asm

s390 version of commit 334bb773 ("x86/kbuild: enable modversions
for symbols exported from asm") so we get also rid of all these
warnings:

WARNING: EXPORT symbol "_mcount" [vmlinux] version generation failed, symbol will not be versioned.
WARNING: EXPORT symbol "memcpy" [vmlinux] version generation failed, symbol will not be versioned.
WARNING: EXPORT symbol "memmove" [vmlinux] version generation failed, symbol will not be versioned.
WARNING: EXPORT symbol "memset" [vmlinux] version generation failed, symbol will not be versioned.
WARNING: EXPORT symbol "save_fpu_regs" [vmlinux] version generation failed, symbol will not be versioned.
WARNING: EXPORT symbol "sie64a" [vmlinux] version generation failed, symbol will not be versioned.
WARNING: EXPORT symbol "sie_exit" [vmlinux] version generation failed, symbol will not be versioned.
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

arch/s390/include/asm/asm-prototypes.h

+#ifndef _ASM_S390_PROTOTYPES_H
+
+#include <linux/kvm_host.h>
+#include <linux/ftrace.h>
+#include <asm/fpu/api.h>
+#include <asm-generic/asm-prototypes.h>
+
+#endif /* _ASM_S390_PROTOTYPES_H */