s390/entry: remove toolchain dependent micro-optimization

Get rid of CONFIG_AS_IS_LLVM in entry.S to make the code a bit more
readable. This removes a micro-optimization, but given that the llvm IAS
limitation will likely stay, just use the version that works with llvm.

See commit 4c25f0ff ("s390/entry: workaround llvm's IAS limitations")
for further details.
Signed-off-by: Heiko Carstens <hca@linux.ibm.com>

arch/s390/kernel/entry.S

@@ -137,19 +137,13 @@ _LPP_OFFSET	= __LC_LPP
 	lgr	%r14,\reg
 	larl	%r13,\start
 	slgr	%r14,%r13
-#ifdef CONFIG_AS_IS_LLVM
 	clgfrl	%r14,.Lrange_size\@
-#else
-	clgfi	%r14,\end - \start
-#endif
 	jhe	\outside_label
-#ifdef CONFIG_AS_IS_LLVM
 	.section .rodata, "a"
 	.align 4
 .Lrange_size\@:
 	.long	\end - \start
 	.previous
-#endif
 	.endm
 
 	.macro SIEEXIT