qga: update guest-suspend-ram and guest-suspend-hybrid descriptions

This patch updates the descriptions of 'guest-suspend-ram' and
'guest-suspend-hybrid' to mention that both commands relies now
on the proper support for wake up from suspend, retrieved by the
'wakeup-suspend-support' attribute of the 'query-current-machine'
QMP command.
Reported-by: NBalamuruhan S <bala24@linux.vnet.ibm.com>
Signed-off-by: NDaniel Henrique Barboza <danielhb413@gmail.com>
Reviewed-by: NMichael Roth <mdroth@linux.vnet.ibm.com>
Message-Id: <20181205194701.17836-3-danielhb413@gmail.com>
Reviewed-by: NMarkus Armbruster <armbru@redhat.com>
Acked-by: NEduardo Habkost <ehabkost@redhat.com>
Signed-off-by: NMarkus Armbruster <armbru@redhat.com>

qga/qapi-schema.json

@@ -567,9 +567,11 @@
 # For the best results it's strongly recommended to have the pm-utils
 # package installed in the guest.
 #
-# IMPORTANT: guest-suspend-ram requires QEMU to support the 'system_wakeup'
-# command.  Thus, it's *required* to query QEMU for the presence of the
-# 'system_wakeup' command before issuing guest-suspend-ram.
+# IMPORTANT: guest-suspend-ram requires working wakeup support in
+# QEMU. You should check QMP command query-current-machine returns
+# wakeup-suspend-support: true before issuing this command. Failure in
+# doing so can result in a suspended guest that QEMU will not be able to
+# awaken, forcing the user to power cycle the guest to bring it back.
 #
 # This command does NOT return a response on success. There are two options
 # to check for success:
@@ -594,9 +596,11 @@
 #
 # This command requires the pm-utils package to be installed in the guest.
 #
-# IMPORTANT: guest-suspend-hybrid requires QEMU to support the 'system_wakeup'
-# command.  Thus, it's *required* to query QEMU for the presence of the
-# 'system_wakeup' command before issuing guest-suspend-hybrid.
+# IMPORTANT: guest-suspend-hybrid requires working wakeup support in
+# QEMU. You should check QMP command query-current-machine returns
+# wakeup-suspend-support: true before issuing this command. Failure in
+# doing so can result in a suspended guest that QEMU will not be able to
+# awaken, forcing the user to power cycle the guest to bring it back.
 #
 # This command does NOT return a response on success. There are two options
 # to check for success: