ARC: .exit.* sections can be discarded in .eh_frame regime

We used to keep the .exit.* sections as linker would fail in final link
due to references from .debug_frame which itself could not be discardrd
due to the forced "write,alloc" attributes for it.

|   LD      init/built-in.o
| `.exit.text' referenced in section `.debug_frame' of arch/arc/built-in.o: defined in discarded section `.exit.text' of arch/arc/built-in.o
| Makefile:949: recipe for target 'vmlinux' failed

With .debug_frame now retired, this hack is no longer needed.
kernel binary is now a little bit smaller as well.

closes STAR 9000549913
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>

arch/arc/kernel/vmlinux.lds.S

@@ -82,14 +82,6 @@ SECTIONS
 
 	PERCPU_SECTION(L1_CACHE_BYTES)
 
-	/*
-	 * .exit.text is discard at runtime, not link time, to deal with
-	 * references from unwinding sections
-	 * It will be init freed, being inside [__init_start : __init_end]
-	 */
-	.exit.text : { EXIT_TEXT }
-	.exit.data : { EXIT_DATA }
-
 	. = ALIGN(PAGE_SIZE);
 	__init_end = .;