xtensa: use call instead of callx in assembly code

Now that xtensa assembly sources are compiled with -mlongcalls let the
assembler and linker relax call instructions into l32r + callx where
needed. This change makes the code cleaner and potentially a bit faster.

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>

arch/xtensa/kernel/coprocessor.S

@@ -212,8 +212,7 @@ ENDPROC(coprocessor_restore)
 ENTRY(fast_coprocessor_double)
 
 	wsr	a0, excsave1
-	movi	a0, unrecoverable_exception
-	callx0	a0
+	call0	unrecoverable_exception
 
 ENDPROC(fast_coprocessor_double)