Include hw/boards.h a bit less

hw/boards.h pulls in almost 60 headers.  The less we include it into
headers, the better.  As a first step, drop superfluous inclusions,
and downgrade some more to what's actually needed.  Gets rid of just
one inclusion into a header.

Cc: Eduardo Habkost <ehabkost@redhat.com>
Cc: Marcel Apfelbaum <marcel.apfelbaum@gmail.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Alistair Francis <alistair.francis@wdc.com>
Message-Id: <20190812052359.30071-23-armbru@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Tested-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Eduardo Habkost <ehabkost@redhat.com>

target/i386/hvf/hvf.c

@@ -66,7 +66,6 @@
 
 #include "exec/address-spaces.h"
 #include "hw/i386/apic_internal.h"
-#include "hw/boards.h"
 #include "qemu/main-loop.h"
 #include "sysemu/accel.h"
 #include "sysemu/sysemu.h"

target/i386/hvf/x86_task.c

@@ -27,7 +27,6 @@
 #include <Hypervisor/hv_vmx.h>
 
 #include "hw/i386/apic_internal.h"
-#include "hw/boards.h"
 #include "qemu/main-loop.h"
 #include "sysemu/accel.h"
 #include "sysemu/sysemu.h"

target/i386/machine.c

@@ -1,7 +1,6 @@
 #include "qemu/osdep.h"
 #include "cpu.h"
 #include "exec/exec-all.h"
-#include "hw/boards.h"
 #include "hw/i386/pc.h"
 #include "hw/isa/isa.h"
 #include "migration/cpu.h"

target/i386/whpx-all.c

@@ -18,7 +18,6 @@
 #include "sysemu/sysemu.h"
 #include "sysemu/cpus.h"
 #include "qemu/main-loop.h"
-#include "hw/boards.h"
 #include "qemu/error-report.h"
 #include "qapi/error.h"
 #include "migration/blocker.h"