powerpc: Fixes to get the merged kernel to boot on powermac.

This merges ppc_ksyms.c, puts back the actual do_execve call in
sys_execve, makes init_MMU call find_end_of_memory rather than
ppc_md.find_end_of_memory (every platform has a device tree
with a /memory node now, right?) and fixes some problems with the
mpic initialization on newworld powermacs.

Signed-off-by: Paul Mackerras <paulus@samba.org>

arch/powerpc/kernel/process.c

@@ -601,6 +601,8 @@ int sys_execve(unsigned long a0, unsigned long a1, unsigned long a2,
 	flush_fp_to_thread(current);
 	flush_altivec_to_thread(current);
 	flush_spe_to_thread(current);
+	error = do_execve(filename, (char __user * __user *) a1,
+			  (char __user * __user *) a2, regs);
 	if (error == 0) {
 		task_lock(current);
 		current->ptrace &= ~PT_DTRACE;