xtensa: use DWARF_DEBUG in the vmlinux.lds.S

Xtensa doesn't have anything custom in its debug sections list. Use
macro DWARF_DEBUG instead of opencoding it.
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>

arch/xtensa/kernel/vmlinux.lds.S

@@ -301,23 +301,7 @@ SECTIONS
   .xt.lit : { *(.xt.lit) }
   .xt.prop : { *(.xt.prop) }
 
-  .debug  0 :  { *(.debug) }
-  .line  0 :  { *(.line) }
-  .debug_srcinfo  0 :  { *(.debug_srcinfo) }
-  .debug_sfnames  0 :  { *(.debug_sfnames) }
-  .debug_aranges  0 :  { *(.debug_aranges) }
-  .debug_pubnames  0 :  { *(.debug_pubnames) }
-  .debug_info  0 :  { *(.debug_info) }
-  .debug_abbrev  0 :  { *(.debug_abbrev) }
-  .debug_line  0 :  { *(.debug_line) }
-  .debug_frame  0 :  { *(.debug_frame) }
-  .debug_str  0 :  { *(.debug_str) }
-  .debug_loc  0 :  { *(.debug_loc) }
-  .debug_macinfo  0 :  { *(.debug_macinfo) }
-  .debug_weaknames  0 :  { *(.debug_weaknames) }
-  .debug_funcnames  0 :  { *(.debug_funcnames) }
-  .debug_typenames  0 :  { *(.debug_typenames) }
-  .debug_varnames  0 :  { *(.debug_varnames) }
+  DWARF_DEBUG
 
   .xt.insn 0 :
   {