arch/tile: stop mentioning the "kvm" subdirectory

It causes "make clean" to fail, for example.  Once we have KVM support
complete, we'll reinstate the subdir reference.
Signed-off-by: NChris Metcalf <cmetcalf@tilera.com>

arch/tile/Makefile

@@ -54,8 +54,6 @@ libs-y		+= $(LIBGCC_PATH)
 # See arch/tile/Kbuild for content of core part of the kernel
 core-y		+= arch/tile/
 
-core-$(CONFIG_KVM) += arch/tile/kvm/
-
 ifdef TILERA_ROOT
 INSTALL_PATH ?= $(TILERA_ROOT)/tile/boot
 endif