drivers/misc/sgi-xp: Remove orphan declarations from drivers/misc/sgi-xp/xp.h

Remove the following orphan declarations from drivers/misc/sgi-xp/xp.h:
1. xp_nofault_PIOR_target
2. xp_error_PIOR
3. xp_nofault_PIOR

They have been removed since commit 9726bfcdb977 ("misc/sgi-xp:
remove SGI SN2 support"), so remove them.

Reviewed-by: Steve Wahl <[e-mail]>
Signed-off-by: Gaosheng Cui <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Greg Kroah-Hartman <[e-mail]>

drivers/misc/sgi-xp/xp.h

···
 extern enum xp_retval (*xp_expand_memprotect) (unsigned long, unsigned long);
 extern enum xp_retval (*xp_restrict_memprotect) (unsigned long, unsigned long);
 
-extern u64 xp_nofault_PIOR_target;
-extern int xp_nofault_PIOR(void *);
-extern int xp_error_PIOR(void);
-
 extern struct device *xp;
 extern enum xp_retval xp_init_uv(void);
 extern void xp_exit_uv(void);