powerpc/pseries: Double NR_CPUS in defconfig

Anticipating growth in coming years, we should ensure we are getting a
good lead on testing.

Signed-off-by: Nishanth Aravamudan <nacc@us.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

arch/powerpc/configs/pseries_defconfig

@@ -2,7 +2,7 @@ CONFIG_PPC64=y
 CONFIG_ALTIVEC=y
 CONFIG_VSX=y
 CONFIG_SMP=y
-CONFIG_NR_CPUS=1024
+CONFIG_NR_CPUS=2048
 CONFIG_EXPERIMENTAL=y
 CONFIG_SYSVIPC=y
 CONFIG_POSIX_MQUEUE=y