x86/setup: add missing headers

The missing headers declare variables 'xen_cpuidle' and 'use_invpcid'
that are then defined inside the file.
This is undesirable and also violates MISRA C:2012 Rule 8.4.
Adding suitable "#include"s resolves the issue.

The type of the variable 'xen_cpuidle' also changes according to
s/s8/int8_t/.

Fixes: 3eab82196b ("x86: PIT broadcast to fix local APIC timer stop issue for Deep C state")
Fixes: 63dc135aea ("x86: invpcid support")
Signed-off-by: Nicola Vetrini <nicola.vetrini@bugseng.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
Acked-by: Jan Beulich <jbeulich@suse.com>

xen/arch/x86/setup.c

@@ -47,10 +47,12 @@
 #include <asm/mach-generic/mach_apic.h> /* for generic_apic_probe */
 #include <asm/setup.h>
 #include <xen/cpu.h>
+#include <xen/cpuidle.h>
 #include <asm/nmi.h>
 #include <asm/alternative.h>
 #include <asm/mc146818rtc.h>
 #include <asm/cpu-policy.h>
+#include <asm/invpcid.h>
 #include <asm/spec_ctrl.h>
 #include <asm/guest.h>
 #include <asm/microcode.h>
@@ -88,7 +90,7 @@ boolean_param("noapic", skip_ioapic_setup);
 
 /* **** Linux config option: propagated to domain0. */
 /* xen_cpuidle: xen control cstate. */
-s8 __read_mostly xen_cpuidle = -1;
+int8_t __read_mostly xen_cpuidle = -1;
 boolean_param("cpuidle", xen_cpuidle);
 
 #ifndef NDEBUG

xen/include/xen/cpuidle.h

@@ -86,7 +86,7 @@ struct cpuidle_governor
     void (*reflect)         (struct acpi_processor_power *dev);
 };
 
-extern s8 xen_cpuidle;
+extern int8_t xen_cpuidle;
 extern struct cpuidle_governor *cpuidle_current_governor;
 
 bool cpuidle_using_deep_cstate(void);