Update libvpx snapshot to v0.9.7-p1 (Cayuga).

source/libvpx/vp8/vp8cx.mk

Index: source/libvpx/vp8/vp8cx.mk
===================================================================
--- source/libvpx/vp8/vp8cx.mk	(revision 96967)
+++ source/libvpx/vp8/vp8cx.mk	(working copy)
@@ -52,6 +52,8 @@
 VP8_CX_SRCS-yes += encoder/encodemb.h
 VP8_CX_SRCS-yes += encoder/encodemv.h
 VP8_CX_SRCS-yes += encoder/firstpass.h
+VP8_CX_SRCS-yes += encoder/lookahead.c
+VP8_CX_SRCS-yes += encoder/lookahead.h
 VP8_CX_SRCS-yes += encoder/mcomp.h
 VP8_CX_SRCS-yes += encoder/modecosts.h
 VP8_CX_SRCS-yes += encoder/onyx_int.h
@@ -75,12 +77,12 @@
 VP8_CX_SRCS-yes += encoder/sad_c.c
 VP8_CX_SRCS-yes += encoder/segmentation.c
 VP8_CX_SRCS-yes += encoder/segmentation.h
-VP8_CX_SRCS-$(CONFIG_PSNR) += encoder/ssim.c
+VP8_CX_SRCS-$(CONFIG_INTERNAL_STATS) += encoder/ssim.c
 VP8_CX_SRCS-yes += encoder/tokenize.c
 VP8_CX_SRCS-yes += encoder/treewriter.c
 VP8_CX_SRCS-yes += encoder/variance_c.c
-VP8_CX_SRCS-$(CONFIG_PSNR) += common/postproc.h
-VP8_CX_SRCS-$(CONFIG_PSNR) += common/postproc.c
+VP8_CX_SRCS-$(CONFIG_INTERNAL_STATS) += common/postproc.h
+VP8_CX_SRCS-$(CONFIG_INTERNAL_STATS) += common/postproc.c
 VP8_CX_SRCS-yes += encoder/temporal_filter.c
 VP8_CX_SRCS-yes += encoder/temporal_filter.h
 
@@ -115,6 +117,7 @@
 VP8_CX_SRCS-$(HAVE_SSSE3) += encoder/x86/variance_impl_ssse3.asm
 VP8_CX_SRCS-$(HAVE_SSSE3) += encoder/x86/quantize_ssse3.asm
 VP8_CX_SRCS-$(HAVE_SSE4_1) += encoder/x86/sad_sse4.asm
+VP8_CX_SRCS-$(HAVE_SSE4_1) += encoder/x86/quantize_sse4.asm
 VP8_CX_SRCS-$(ARCH_X86)$(ARCH_X86_64) += encoder/x86/quantize_mmx.asm
 VP8_CX_SRCS-$(ARCH_X86)$(ARCH_X86_64) += encoder/x86/encodeopt.asm
 VP8_CX_SRCS-$(ARCH_X86_64) += encoder/x86/ssim_opt.asm