Switch x86_64 over to uapi headers.

Bug: 11559337
Change-Id: Ia0a8dff9194375172d1c89daae917d2d8952ace7
diff --git a/core/combo/TARGET_linux-x86_64.mk b/core/combo/TARGET_linux-x86_64.mk
index 86d29f5..02cb57a 100755
--- a/core/combo/TARGET_linux-x86_64.mk
+++ b/core/combo/TARGET_linux-x86_64.mk
@@ -110,8 +110,8 @@
     KERNEL_HEADERS_COMMON := $(CUSTOM_KERNEL_HEADERS)
     KERNEL_HEADERS_ARCH   := $(CUSTOM_KERNEL_HEADERS)
 else
-    KERNEL_HEADERS_COMMON := $(libc_root)/kernel/common
-    KERNEL_HEADERS_ARCH   := $(libc_root)/kernel/arch-$(TARGET_ARCH)
+    KERNEL_HEADERS_COMMON := $(libc_root)/kernel/uapi
+    KERNEL_HEADERS_ARCH   := $(libc_root)/kernel/uapi/asm-x86 # x86 covers both x86 and x86_64.
 endif
 KERNEL_HEADERS := $(KERNEL_HEADERS_COMMON) $(KERNEL_HEADERS_ARCH)