riscv: mm: Only compile pgtable.c if MMU

commit d650899 upstream.

All functions defined in there depend on MMU, so no need to compile it
for !MMU configs.

Signed-off-by: Alexandre Ghiti <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Palmer Dabbelt <[email protected]>
Signed-off-by: WangYuli <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>

arch/riscv/mm/Makefile

@@ -13,10 +13,9 @@ endif
 KCOV_INSTRUMENT_init.o := n
 
 obj-y += init.o
-obj-$(CONFIG_MMU) += extable.o fault.o pageattr.o
+obj-$(CONFIG_MMU) += extable.o fault.o pageattr.o pgtable.o
 obj-y += cacheflush.o
 obj-y += context.o
-obj-y += pgtable.o
 obj-y += pmem.o
 
 ifeq ($(CONFIG_MMU),y)