x86/mm/pat: Rename <asm/pat.h> => <asm/memtype.h>

pat.h is a file whose main purpose is to provide the memtype_*() APIs.

PAT is the low level hardware mechanism - but the high level abstraction
is memtype.

So name the header <memtype.h> as well - this goes hand in hand with memtype.c
and memtype_interval.c.

Signed-off-by: Ingo Molnar <mingo@kernel.org>

arch/x86/pci/i386.c

@@ -34,7 +34,7 @@
 #include <linux/errno.h>
 #include <linux/memblock.h>
 
-#include <asm/pat.h>
+#include <asm/memtype.h>
 #include <asm/e820/api.h>
 #include <asm/pci_x86.h>
 #include <asm/io_apic.h>