x86: export get_xsave_addr

get_xsave_addr is the API to access XSAVE states, and KVM would
like to use it.  Export it.

Cc: stable@vger.kernel.org
Cc: x86@kernel.org
Cc: H. Peter Anvin <hpa@linux.intel.com>
Acked-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

arch/x86/kernel/xsave.c

@@ -738,3 +738,4 @@ void *get_xsave_addr(struct xsave_struct *xsave, int xstate)
 
 	return (void *)xsave + xstate_comp_offsets[feature];
 }
+EXPORT_SYMBOL_GPL(get_xsave_addr);