powerpc/32: Interchange r1 and r11 in SYSCALL_ENTRY on booke

To better match non booke version of SYSCALL_ENTRY macro,
interchange r1 and r11 in the booke version.

While at it, in both versions use r1 instead of r11 to save
_NIP and _CCR.

All other uses of r11 will go away in next patch, so don't
bother changing them for now.
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/1684c39724a069b0ce1aa82eaee6ec194e354e4e.1622818435.git.christophe.leroy@csgroup.eu

arch/powerpc/kernel/head_32.h

@@ -158,12 +158,12 @@ _ASM_NOKPROBE_SYMBOL(\name\()_virt)
 	stw	r11,GPR1(r1)
 	stw	r11,0(r1)
 	mr	r11, r1
-	stw	r12,_NIP(r11)
+	stw	r12,_NIP(r1)
 	mflr	r12
 	stw	r12, _LINK(r11)
 	mfcr	r12
 	rlwinm	r12,r12,0,4,2	/* Clear SO bit in CR */
-	stw	r12,_CCR(r11)		/* save registers */
+	stw	r12,_CCR(r1)
 #ifdef CONFIG_40x
 	rlwinm	r9,r9,0,14,12		/* clear MSR_WE (necessary?) */
 #endif

arch/powerpc/kernel/head_booke.h

@@ -135,17 +135,18 @@ ALT_FTR_SECTION_END_IFSET(CPU_FTR_EMB_HV)
 #endif
 	mfspr	r9, SPRN_SRR1
 	BOOKE_CLEAR_BTB(r11)
-	lwz	r11, TASK_STACK - THREAD(r10)
+	mr	r11, r1
+	lwz	r1, TASK_STACK - THREAD(r10)
 	rlwinm	r12,r12,0,4,2	/* Clear SO bit in CR */
-	ALLOC_STACK_FRAME(r11, THREAD_SIZE - INT_FRAME_SIZE)
-	stw	r12, _CCR(r11)		/* save various registers */
+	ALLOC_STACK_FRAME(r1, THREAD_SIZE - INT_FRAME_SIZE)
+	stw	r12, _CCR(r1)
 	mflr	r12
-	stw	r12,_LINK(r11)
+	stw	r12,_LINK(r1)
 	mfspr	r12,SPRN_SRR0
-	stw	r1, GPR1(r11)
-	stw	r1, 0(r11)
-	mr	r1, r11
-	stw	r12,_NIP(r11)
+	stw	r11, GPR1(r1)
+	stw	r11, 0(r1)
+	mr	r11, r1
+	stw	r12,_NIP(r1)
 	rlwinm	r9,r9,0,14,12		/* clear MSR_WE (necessary?)	   */
 	lis	r12, STACK_FRAME_REGS_MARKER@ha /* exception frame marker */
 	stw	r2,GPR2(r11)