xtensa: reorganize SR referencing

- reference SRs by names where possible, not by numbers;
- get rid of __stringify around SR names where possible;
- remove unneeded SR names from asm/regs.h;
- add SREG_ prefix to remaining SR names;

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
Signed-off-by: Chris Zankel <chris@zankel.net>
diff --git a/arch/xtensa/kernel/coprocessor.S b/arch/xtensa/kernel/coprocessor.S
index 2bc1e14..54c3be3 100644
--- a/arch/xtensa/kernel/coprocessor.S
+++ b/arch/xtensa/kernel/coprocessor.S
@@ -43,7 +43,7 @@
 /* IO protection is currently unsupported. */
 
 ENTRY(fast_io_protect)
-	wsr	a0, EXCSAVE_1
+	wsr	a0, excsave1
 	movi	a0, unrecoverable_exception
 	callx0	a0
 
@@ -220,7 +220,7 @@
  */
 
 ENTRY(fast_coprocessor_double)
-	wsr	a0, EXCSAVE_1
+	wsr	a0, excsave1
 	movi	a0, unrecoverable_exception
 	callx0	a0
 
@@ -229,13 +229,13 @@
 
 	/* Save remaining registers a1-a3 and SAR */
 
-	xsr	a3, EXCSAVE_1
+	xsr	a3, excsave1
 	s32i	a3, a2, PT_AREG3
-	rsr	a3, SAR
+	rsr	a3, sar
 	s32i	a1, a2, PT_AREG1
 	s32i	a3, a2, PT_SAR
 	mov	a1, a2
-	rsr	a2, DEPC
+	rsr	a2, depc
 	s32i	a2, a1, PT_AREG2
 
 	/*
@@ -248,17 +248,17 @@
 
 	/* Find coprocessor number. Subtract first CP EXCCAUSE from EXCCAUSE */
 
-	rsr	a3, EXCCAUSE
+	rsr	a3, exccause
 	addi	a3, a3, -EXCCAUSE_COPROCESSOR0_DISABLED
 
 	/* Set corresponding CPENABLE bit -> (sar:cp-index, a3: 1<<cp-index)*/
 
 	ssl	a3			# SAR: 32 - coprocessor_number
 	movi	a2, 1
-	rsr	a0, CPENABLE
+	rsr	a0, cpenable
 	sll	a2, a2
 	or	a0, a0, a2
-	wsr	a0, CPENABLE
+	wsr	a0, cpenable
 	rsync
 
 	/* Retrieve previous owner. (a3 still holds CP number) */
@@ -291,7 +291,7 @@
 
 	/* Note that only a0 and a1 were preserved. */
 
-2:	rsr	a3, EXCCAUSE
+2:	rsr	a3, exccause
 	addi	a3, a3, -EXCCAUSE_COPROCESSOR0_DISABLED
 	movi	a0, coprocessor_owner
 	addx4	a0, a3, a0
@@ -321,7 +321,7 @@
 	l32i	a0, a1, PT_SAR
 	l32i	a3, a1, PT_AREG3
 	l32i	a2, a1, PT_AREG2
-	wsr	a0, SAR
+	wsr	a0, sar
 	l32i	a0, a1, PT_AREG0
 	l32i	a1, a1, PT_AREG1