x86: fix missing includes/forward declarations

Signed-off-by: Kent Overstreet <[e-mail]>

arch/x86/include/asm/debugreg.h

···
 #include <linux/bug.h>
 #include <linux/percpu.h>
 #include <uapi/asm/debugreg.h>
+#include <asm/cpufeature.h>
 
 DECLARE_PER_CPU(unsigned long, cpu_dr7);
 

arch/x86/include/asm/paravirt.h

···
 
 #include <asm/paravirt_types.h>
 
+#ifndef __ASSEMBLY__
+struct mm_struct;
+#endif
+
 #ifdef CONFIG_PARAVIRT
 #include <asm/pgtable_types.h>
 #include <asm/asm.h>

arch/x86/include/asm/paravirt_types.h

···
 #define _ASM_X86_PARAVIRT_TYPES_H
 
 #ifndef __ASSEMBLY__
+#include <linux/types.h>
+
 /* These all sit in the .parainstructions section to tell us what to patch. */
 struct paravirt_patch_site {
 	u8 *instr;		/* original instructions */

arch/x86/kernel/fpu/bugs.c

···
 /*
  * x86 FPU bug checks:
  */
+#include <asm/cpufeature.h>
 #include <asm/fpu/api.h>
 
 /*

arch/x86/lib/cache-smp.c

···
 // SPDX-License-Identifier: GPL-2.0
+#include <asm/paravirt.h>
 #include <linux/smp.h>
 #include <linux/export.h>