x86/mtrr: Remove obsolete declaration for mtrr_bp_restore()

mtrr_bp_restore() has been removed in commit 0b9a6a8b ("x86/mtrr: Add a
stop_machine() handler calling only cache_cpu_init()"), but the declaration
was left behind. Remove it.
Signed-off-by: Gaosheng Cui <cuigaosheng1@huawei.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/all/20240824120234.2516830-1-cuigaosheng1@huawei.com

arch/x86/include/asm/mtrr.h

@@ -69,7 +69,6 @@ extern int mtrr_add_page(unsigned long base, unsigned long size,
 			 unsigned int type, bool increment);
 extern int mtrr_del(int reg, unsigned long base, unsigned long size);
 extern int mtrr_del_page(int reg, unsigned long base, unsigned long size);
-extern void mtrr_bp_restore(void);
 extern int mtrr_trim_uncached_memory(unsigned long end_pfn);
 extern int amd_special_default_mtrr(void);
 void mtrr_disable(void);
@@ -117,7 +116,6 @@ static inline int mtrr_trim_uncached_memory(unsigned long end_pfn)
 	return 0;
 }
 #define mtrr_bp_init() do {} while (0)
-#define mtrr_bp_restore() do {} while (0)
 #define mtrr_disable() do {} while (0)
 #define mtrr_enable() do {} while (0)
 #define mtrr_generic_set_state() do {} while (0)