CRIS: Change DEFINE_PER_CPU of current_pgd to be non volatile.

The DEFINE_PER_CPU of current_pgd was on CRIS defined using volatile,
which is not needed. Remove volatile.

Tested on an ARTPEC-3 (CRISv32) board.

tj: extern DEFINE_PER_CPU() replaced with DECLARE_PER_CPU()

[ Impact: code cleanup ]
Signed-off-by: Jesper Nilsson <jesper.nilsson@axis.com>
Signed-off-by: Tejun Heo <tj@kernel.org>

arch/cris/include/asm/mmu_context.h

@@ -17,7 +17,8 @@ extern void switch_mm(struct mm_struct *prev, struct mm_struct *next,
  * registers like cr3 on the i386
  */
 
-extern volatile DEFINE_PER_CPU(pgd_t *,current_pgd); /* defined in arch/cris/mm/fault.c */
+/* defined in arch/cris/mm/fault.c */
+DECLARE_PER_CPU(pgd_t *, current_pgd);
 
 static inline void enter_lazy_tlb(struct mm_struct *mm, struct task_struct *tsk)
 {

arch/cris/mm/fault.c

@@ -29,7 +29,7 @@ extern void die_if_kernel(const char *, struct pt_regs *, long);
 
 /* current active page directory */
 
-volatile DEFINE_PER_CPU(pgd_t *,current_pgd);
+DEFINE_PER_CPU(pgd_t *, current_pgd);
 unsigned long cris_signal_return_page;
 
 /*