arch/x86: drop own definition of pgd,p4d_leaf

We provide generic definitions of pXd_leaf in pgtable.h when the arch do
not define their own, where the generic pXd_leaf always return false.

Although x86 defines {pgd,p4d}_leaf, they end up being a no-op, so drop
them and make them fallback to the generic one.

Link: https://lkml.kernel.org/r/bcd6ab8246348f18fdc77694e321ee6458f05781.1720597744.git.christophe.leroy@csgroup.eu


Signed-off-by: Oscar Salvador <osalvador@suse.de>
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Reviewed-by: Peter Xu <peterx@redhat.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Borislav Petkov (AMD) <bp@alien8.de>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>