[S390] fix s390 assembler code alignments

The alignment is missing for various global symbols in s390 assembly code.
With a recent gcc and an instruction like stgrl this can lead to a
specification exception if the instruction uses such a mis-aligned address.

Specify the alignment explicitely and while add it define __ALIGN for s390
and use the ENTRY define to save some lines of code.

Signed-off-by: Jan Glauber <jang@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
diff --git a/arch/s390/kernel/switch_cpu64.S b/arch/s390/kernel/switch_cpu64.S
index 5be3f43..fcc42d7 100644
--- a/arch/s390/kernel/switch_cpu64.S
+++ b/arch/s390/kernel/switch_cpu64.S
@@ -5,6 +5,7 @@
  *
  */
 
+#include <linux/linkage.h>
 #include <asm/asm-offsets.h>
 #include <asm/ptrace.h>
 
@@ -16,9 +17,7 @@
 #	     %r6 - destination cpu
 
 	.section .text
-	.align 4
-	.globl smp_switch_to_cpu
-smp_switch_to_cpu:
+ENTRY(smp_switch_to_cpu)
 	stmg	%r6,%r15,__SF_GPRS(%r15)
 	lgr	%r1,%r15
 	aghi	%r15,-STACK_FRAME_OVERHEAD
@@ -31,8 +30,7 @@
 	brc	2,2b			/* busy, try again */
 3:	j	3b
 
-	.globl	smp_restart_cpu
-smp_restart_cpu:
+ENTRY(smp_restart_cpu)
 	larl	%r1,.gprregs
 	lmg	%r0,%r15,0(%r1)
 1:	sigp	%r0,%r5,__SIGP_SENSE	/* Wait for calling CPU */