arm64: Fix compat register mappings

commit 5accd17d upstream.

For reasons not entirely apparent, but now enshrined in history, the
architectural mapping of AArch32 banked registers to AArch64 registers
actually orders SP_<mode> and LR_<mode> backwards compared to the
intuitive r13/r14 order, for all modes except FIQ.

Fix the compat_<reg>_<mode> macros accordingly, in the hope of avoiding
subtle bugs with KVM and AArch32 guests.
Signed-off-by: Robin Murphy <robin.murphy@arm.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Luis Henriques <luis.henriques@canonical.com>

arch/arm64/include/asm/ptrace.h

@@ -76,14 +76,14 @@
 #define compat_sp	regs[13]
 #define compat_lr	regs[14]
 #define compat_sp_hyp	regs[15]
-#define compat_sp_irq	regs[16]
-#define compat_lr_irq	regs[17]
-#define compat_sp_svc	regs[18]
-#define compat_lr_svc	regs[19]
-#define compat_sp_abt	regs[20]
-#define compat_lr_abt	regs[21]
-#define compat_sp_und	regs[22]
-#define compat_lr_und	regs[23]
+#define compat_lr_irq	regs[16]
+#define compat_sp_irq	regs[17]
+#define compat_lr_svc	regs[18]
+#define compat_sp_svc	regs[19]
+#define compat_lr_abt	regs[20]
+#define compat_sp_abt	regs[21]
+#define compat_lr_und	regs[22]
+#define compat_sp_und	regs[23]
 #define compat_r8_fiq	regs[24]
 #define compat_r9_fiq	regs[25]
 #define compat_r10_fiq	regs[26]