ARC: [plat-eznps] handle extra aux regs #2: kernel/entry exit

Preserve eflags and gpa1 aux during entry/exit into kernel as these
could be modified by kernel mode

These registers used by compare exchange instructions.
  - GPA1 is used for compare value,
  - EFLAGS got bit reflects atomic operation response.

EFLAGS is zeroed for each new user task so it won't get its
parent value.

Signed-off-by: Liav Rehana <liavr@mellanox.com>
Signed-off-by: Noam Camus <noamc@ezchip.com>
Signed-off-by: Vineet Gupta <vgupta@synopsys.com>

arch/arc/include/asm/ptrace.h

@@ -19,6 +19,11 @@
 #ifdef CONFIG_ISA_ARCOMPACT
 struct pt_regs {
 
+#ifdef CONFIG_ARC_PLAT_EZNPS
+	unsigned long eflags;	/* Extended FLAGS */
+	unsigned long gpa1;	/* General Purpose Aux */
+#endif
+
 	/* Real registers */
 	unsigned long bta;	/* bta_l1, bta_l2, erbta */