arch/tile: avoid exporting a symbol no longer used by gcc

An earlier Tilera compiler generated calls to an "__ll_mul"
function for long long multiplication.  Our libgcc supported that
as an alias for the normal __muldi3 routine, so we made it available
to kernel modules as well.  However, for a while now the compiler
has internally been generating only the standard __muldi3 symbol,
and the version we are giving back to the community does not have
the __ll_mul alias, so we are removing it from the kernel too.
Signed-off-by: NChris Metcalf <cmetcalf@tilera.com>

arch/tile/lib/exports.c

@@ -79,8 +79,6 @@ EXPORT_SYMBOL(__umoddi3);
 int64_t __moddi3(int64_t dividend, int64_t divisor);
 EXPORT_SYMBOL(__moddi3);
 #ifndef __tilegx__
-uint64_t __ll_mul(uint64_t n0, uint64_t n1);
-EXPORT_SYMBOL(__ll_mul);
 int64_t __muldi3(int64_t, int64_t);
 EXPORT_SYMBOL(__muldi3);
 uint64_t __lshrdi3(uint64_t, unsigned int);