libpayload: Fix missed CONFIG_ -> CONFIG_LP_ substitutions

Change-Id: I1c64a9a649398ebe2eda179907c470f99caa9fc3
Signed-off-by: Nico Huber <nico.h@gmx.de>
Reviewed-on: http://review.coreboot.org/7056
Tested-by: build bot (Jenkins)
Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net>
Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>
diff --git a/payloads/libpayload/sample/Makefile b/payloads/libpayload/sample/Makefile
index 2029209..0ac1839 100644
--- a/payloads/libpayload/sample/Makefile
+++ b/payloads/libpayload/sample/Makefile
@@ -31,9 +31,9 @@
 include ../.xcompile
 include ../.config
 
-ARCH-$(CONFIG_ARCH_ARMV)   := arm
-ARCH-$(CONFIG_ARCH_POWERPC) := powerpc
-ARCH-$(CONFIG_ARCH_X86)     := i386
+ARCH-$(CONFIG_LP_ARCH_ARMV)    := arm
+ARCH-$(CONFIG_LP_ARCH_POWERPC) := powerpc
+ARCH-$(CONFIG_LP_ARCH_X86)     := i386
 
 CC := $(CC_$(ARCH-y))
 AS := $(AS_$(ARCH-y))