SPARC64: Fix memory controller register access when non-SMP.

[SPARC64]: Fix memory controller register access when non-SMP.

[ Upstream commit: b332b8bc ]

get_cpu() always returns zero on non-SMP builds, but we
really want the physical cpu number in this code in order
to do the right thing.

Based upon a non-SMP kernel boot failure report from Bernd Zeimetz.

Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>