x86/microcode: Initialize the driver late when facilities are up

Running microcode_init() from setup_arch() is a bad idea because
not even kmalloc() is ready at that point and the loader does
all kinds of allocations and init/registration with various
subsystems.

Make it a late initcall when required facilities are initialized
so that the microcode driver initialization can succeed too.

Reported-and-tested-by: Markus Trippelsdorf <markus@trippelsdorf.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20151120112400.GC4028@pd.tnic
Signed-off-by: Ingo Molnar <mingo@kernel.org>

arch/x86/kernel/cpu/microcode/core.c

@@ -698,3 +698,4 @@ int __init microcode_init(void)
 	return error;
 
 }
+late_initcall(microcode_init);

arch/x86/kernel/setup.c

@@ -1250,8 +1250,6 @@ void __init setup_arch(char **cmdline_p)
 	if (efi_enabled(EFI_BOOT))
 		efi_apply_memmap_quirks();
 #endif
-
-	microcode_init();
 }
 
 #ifdef CONFIG_X86_32