[S390] move (io|sysc)_restore_trace_psw into .data section

The sysc_restore_trace_psw and io_restore_trace_psw storage locations
are created in the .text section. When creating and IPLing from a named
saved system (NSS), writing to these locations causes a protection exception
(because the .text section is mapped as shared read-only in the NSS).

To permit write access, move the storage locations into the .data section.

The problem occurs only when CONFIG_TRACE_IRQFLAGS is set.
The git commmit that has introduced these variables is:
411788ea7fca01ee803af8225ac35807b4d02050

Signed-off-by: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
diff --git a/arch/s390/kernel/entry64.S b/arch/s390/kernel/entry64.S
index f6618e9..009ca61 100644
--- a/arch/s390/kernel/entry64.S
+++ b/arch/s390/kernel/entry64.S
@@ -284,10 +284,12 @@
 sysc_done:
 
 #ifdef CONFIG_TRACE_IRQFLAGS
+	.section .data,"aw",@progbits
 	.align	8
 	.globl sysc_restore_trace_psw
 sysc_restore_trace_psw:
 	.quad	0, sysc_restore_trace
+	.previous
 #endif
 
 #
@@ -595,10 +597,12 @@
 io_done:
 
 #ifdef CONFIG_TRACE_IRQFLAGS
+	.section .data,"aw",@progbits
 	.align	8
 	.globl io_restore_trace_psw
 io_restore_trace_psw:
 	.quad	0, io_restore_trace
+	.previous
 #endif
 
 #