powerpc/pseries: Add hypercall wrappers for hash page table resizing

This adds the hypercall numbers and wrapper functions for the hash page
table resizing hypercalls.

These hypercall numbers are defined in the PAPR ACR "HPT resizing
option".

It also adds a new firmware feature flag to track the presence of the
HPT resizing calls.

Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Reviewed-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
diff --git a/arch/powerpc/include/asm/hvcall.h b/arch/powerpc/include/asm/hvcall.h
index 77ff1ba..490c4b9 100644
--- a/arch/powerpc/include/asm/hvcall.h
+++ b/arch/powerpc/include/asm/hvcall.h
@@ -276,6 +276,8 @@
 #define H_GET_MPP_X		0x314
 #define H_SET_MODE		0x31C
 #define H_CLEAR_HPT		0x358
+#define H_RESIZE_HPT_PREPARE	0x36C
+#define H_RESIZE_HPT_COMMIT	0x370
 #define H_SIGNAL_SYS_RESET	0x380
 #define MAX_HCALL_OPCODE	H_SIGNAL_SYS_RESET