ppc: fix incorrect spelling of PowerMac

PowerMac is spelled as PowerMAC (Media Access Control) in some places.
This is misleading.

Resolves: https://gitlab.com/qemu-project/qemu/-/issues/2297
Signed-off-by: Tejas Vipin <tejasvipin76@gmail.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Michael Tokarev <mjt@tls.msk.ru>
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>

docs/system/ppc/powermac.rst

@@ -4,8 +4,8 @@ PowerMac family boards (``g3beige``, ``mac99``)
 Use the executable ``qemu-system-ppc`` to simulate a complete PowerMac
 PowerPC system.
 
-- ``g3beige``              Heathrow based PowerMAC
-- ``mac99``                Mac99 based PowerMAC
+- ``g3beige``              Heathrow based PowerMac
+- ``mac99``                Mac99 based PowerMac
 
 Supported devices
 -----------------

hw/ppc/mac_newworld.c

@@ -571,7 +571,7 @@ static void core99_machine_class_init(ObjectClass *oc, void *data)
     MachineClass *mc = MACHINE_CLASS(oc);
     FWPathProviderClass *fwc = FW_PATH_PROVIDER_CLASS(oc);
 
-    mc->desc = "Mac99 based PowerMAC";
+    mc->desc = "Mac99 based PowerMac";
     mc->init = ppc_core99_init;
     mc->block_default_type = IF_IDE;
     /* SMP is not supported currently */

hw/ppc/mac_oldworld.c

@@ -411,7 +411,7 @@ static void heathrow_class_init(ObjectClass *oc, void *data)
     MachineClass *mc = MACHINE_CLASS(oc);
     FWPathProviderClass *fwc = FW_PATH_PROVIDER_CLASS(oc);
 
-    mc->desc = "Heathrow based PowerMAC";
+    mc->desc = "Heathrow based PowerMac";
     mc->init = ppc_heathrow_init;
     mc->block_default_type = IF_IDE;
     /* SMP is not supported currently */