modularization: hypervisor initilization component

hypervisor initilization component triggered by boot component,
and it calls different components initilization functions from
the highest layer.

this patch added init.c and move reorged cpu init functions into
it, keep hardware management functions in cpu.c but move other
components' init function into init.c.

the hypervisor initilization components will call:
- init_cpu_pre
- init_cpu_post
- init_bsp
- init_debug_pre
- init_debug_post
- init_guest
- init_passthru
- enter_guest_mode

the hypervisor initilization component include files:
arch/x86/init.c
include/arch/x86/init.h

this component is higest layer, so there is no reverse dependencies for it.

v2:
- separate into 2 patches, 1 for reorg, 1 for pure move.

Tracked-On: #1842
Signed-off-by: Jason Chen CJ <jason.cj.chen@intel.com>
Acked-by: Xu, Anthony <anthony.xu@intel.com>

hypervisor/include/arch/x86/init.h

@@ -0,0 +1,14 @@
+/*
+ * Copyright (C) <2018> Intel Corporation
+ * SPDX-License-Identifier: BSD-3-Clause
+ */
+
+#ifndef	INIT_H
+
+/* hypervisor stack bottom magic('intl') */
+#define SP_BOTTOM_MAGIC    0x696e746cUL
+
+void bsp_boot_init(void);
+void cpu_secondary_init(void);
+
+#endif /* INIT_H*/