[PATCH] ppc64: Update g5_defconfig for ARCH=powerpc

This patch updates g5_defconfig for ARCH=powerpc in order to add the SMU
support & thermal drivers to it, the pmac sound driver (works on some
G5s) and replaces rivafb with nvidiafb which works better for the cards
found in G5 based machines.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>