mshv: hide x86-specific functions on arm64

The hv_sleep_notifiers_register() and hv_machine_power_off() functions are
only called and declared on x86, but cause a warning on arm64:

drivers/hv/mshv_common.c:210:6: error: no previous prototype for 'hv_sleep_notifiers_register' [-Werror=missing-prototypes]
  210 | void hv_sleep_notifiers_register(void)
      |      ^~~~~~~~~~~~~~~~~~~~~~~~~~~
drivers/hv/mshv_common.c:224:6: error: no previous prototype for 'hv_machine_power_off' [-Werror=missing-prototypes]
  224 | void hv_machine_power_off(void)
      |      ^~~~~~~~~~~~~~~~~~~~

Hide both inside of an #ifdef block.

Fixes: f0be260 ("mshv: Use reboot notifier to configure sleep state")
Fixes: 615a6e7 ("mshv: Cleanly shutdown root partition with MSHV")
Signed-off-by: Arnd Bergmann <[email protected]>
Signed-off-by: Wei Liu <[email protected]>

Author: arndb

drivers/hv/mshv_common.c

@@ -142,6 +142,7 @@ int hv_call_get_partition_property(u64 partition_id,
 }
 EXPORT_SYMBOL_GPL(hv_call_get_partition_property);
 
+#ifdef CONFIG_X86
 /*
  * Corresponding sleep states have to be initialized in order for a subsequent
  * HVCALL_ENTER_SLEEP_STATE call to succeed. Currently only S5 state as per
@@ -237,3 +238,4 @@ void hv_machine_power_off(void)
 	BUG();
 
 }
+#endif