hv:move 'udelay' to timer.c

-- move this api from misc.c to timer.c to avoid
   reverse dependency, and remove misc.c

Tracked-On: #1842
Signed-off-by: Mingqiang Chi <mingqiang.chi@intel.com>

hypervisor/include/arch/x86/timer.h

@@ -49,6 +49,8 @@ struct hv_timer {
 
 #define CYCLES_PER_MS	us_to_ticks(1000U)
 
+void udelay(uint32_t us);
+
 /**
  * @brief convert us to ticks.
  *