ARC: Fix build breakage for !CONFIG_ARC_DW2_UNWIND

Fixes: ec7ac6a (ARC: switch to generic ENTRY/END assembler annotations)
Reported-by: Anton Kolesov <akolesov@synopsys.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>

arch/arc/kernel/ctx_sw_asm.S

@@ -10,9 +10,9 @@
  *  -This is the more "natural" hand written assembler
  */
 
+#include <linux/linkage.h>
 #include <asm/entry.h>       /* For the SAVE_* macros */
 #include <asm/asm-offsets.h>
-#include <asm/linkage.h>
 
 #define KSP_WORD_OFF 	((TASK_THREAD + THREAD_KSP) / 4)