hv: clean up spinlock

- move spinlock_init and spinlock_obtain to spinlock.h as inline APIs
- remove spinlock.c

Tracked-On: #861
Signed-off-by: Shiqing Gao <shiqing.gao@intel.com>
Acked-by: Anthony Xu <anthony.xu@intel.com>

hypervisor/lib/spinlock.c

@@ -1,34 +0,0 @@
-/*
- * Copyright (C) 2018 Intel Corporation. All rights reserved.
- *
- * SPDX-License-Identifier: BSD-3-Clause
- */
-
-#include <hv_lib.h>
-
-void spinlock_init(spinlock_t *lock)
-{
-	(void)memset(lock, 0U, sizeof(spinlock_t));
-}
-
-void spinlock_obtain(spinlock_t *lock)
-{
-
-	/* The lock function atomically increments and exchanges the head
-	 * counter of the queue. If the old head of the queue is equal to the
-	 * tail, we have locked the spinlock. Otherwise we have to wait.
-	 */
-
-	asm volatile ("   lock xaddl %%eax,%[head]\n"
-		      "   cmpl %%eax,%[tail]\n"
-		      "   jz 1f\n"
-		      "2: pause\n"
-		      "   cmpl %%eax,%[tail]\n"
-		      "   jnz 2b\n"
-		      "1:\n"
-		      :
-		      : "a" (1),
-		      [head] "m"(lock->head),
-		      [tail] "m"(lock->tail)
-		      : "cc", "memory");
-}