[POWERPC] Raise the upper limit of NR_CPUS and move the pacas into the BSS

This adds the required functionality to fill in all pacas at runtime.

With NR_CPUS=1024
text    data     bss     dec     hex filename
 137 1704032       0 1704169  1a00e9 arch/powerpc/kernel/paca.o :Before
 121 1179744  524288 1704153  1a00d9 arch/powerpc/kernel/paca.o :After

Also remove unneeded #includes from arch/powerpc/kernel/paca.c

Signed-off-by: Tony Breeds <tony@bakeyournoodle.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>

arch/powerpc/kernel/setup_64.c

@@ -170,6 +170,9 @@ void __init setup_paca(int cpu)
 
 void __init early_setup(unsigned long dt_ptr)
 {
+	/* Fill in any unititialised pacas */
+	initialise_pacas();
+
 	/* Identify CPU type */
 	identify_cpu(0, mfspr(SPRN_PVR));