powerpc: Uncomment and make enable_kernel_vsx() routine available

enable_kernel_vsx() function was commented since anything was using
it. However, vmx-crypto driver uses VSX instructions which are
only available if VSX is enable. Otherwise it rises an exception oops.

This patch uncomment enable_kernel_vsx() routine and makes it available.

Signed-off-by: Leonidas S. Barbosa <leosilva@linux.vnet.ibm.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
diff --git a/arch/powerpc/include/asm/switch_to.h b/arch/powerpc/include/asm/switch_to.h
index 58abeda..15cca17 100644
--- a/arch/powerpc/include/asm/switch_to.h
+++ b/arch/powerpc/include/asm/switch_to.h
@@ -29,6 +29,7 @@
 
 extern void enable_kernel_fp(void);
 extern void enable_kernel_altivec(void);
+extern void enable_kernel_vsx(void);
 extern int emulate_altivec(struct pt_regs *);
 extern void __giveup_vsx(struct task_struct *);
 extern void giveup_vsx(struct task_struct *);