s390: move _text to an actual .text start

Since the uncompressed image .text section starts at 0x100000 now there
is no need to redefine _text to something else to make perf happy.
Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>

arch/s390/kernel/vmlinux.lds.S

@@ -34,13 +34,8 @@ SECTIONS
 	_stext = .;		/* Start of text section */
 	.text : {
 		/* Text and read-only data */
+		_text = .;
 		HEAD_TEXT
-		/*
-		 * E.g. perf doesn't like symbols starting at address zero,
-		 * therefore skip the initial PSW and channel program located
-		 * at address zero and let _text start at 0x200.
-		 */
-	_text = 0x200;
 		TEXT_TEXT
 		SCHED_TEXT
 		CPUIDLE_TEXT