misc: fix naming scheme of compatiblity arrays

Since merge 31ed4188 ("Merge
remote-tracking branch
'remotes/elmarco/tags/machine-props-pull-request' into staging"), the
compat arrays are in lowercase.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
Message-Id: <20190708204909.10891-1-marcandre.lureau@redhat.com>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>

docs/devel/migration.rst

@@ -314,7 +314,7 @@ For example:
 
    a) Add a new property using ``DEFINE_PROP_BOOL`` - e.g. support-foo and
       default it to true.
-   b) Add an entry to the ``HW_COMPAT_`` for the previous version that sets
+   b) Add an entry to the ``hw_compat_`` for the previous version that sets
       the property to false.
    c) Add a static bool  support_foo function that tests the property.
    d) Add a subsection with a .needed set to the support_foo function

hw/i386/pc_piix.c

@@ -312,7 +312,7 @@ else {
  * pc_compat_*() functions that run on machine-init time and
  * change global QEMU state are deprecated. Please don't create
  * one, and implement any pc-*-2.4 (and newer) compat code in
- * HW_COMPAT_*, PC_COMPAT_*, or * pc_*_machine_options().
+ * hw_compat_*, pc_compat_*, or * pc_*_machine_options().
  */
 
 static void pc_compat_2_3_fn(MachineState *machine)