LoongArch: Select HAVE_DEBUG_KMEMLEAK to support kmemleak

We can see that DEBUG_KMEMLEAK depends on HAVE_DEBUG_KMEMLEAK after
commit b69ec42b1b ("Kconfig: clean up the long arch list for the
DEBUG_KMEMLEAK config option"), just select HAVE_DEBUG_KMEMLEAK to
support kmemleak on LoongArch.

Signed-off-by: Tiezhu Yang <yangtiezhu@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>

Documentation/features/debug/kmemleak/arch-support.txt

@@ -13,7 +13,7 @@
     |        csky: |  ok  |
     |     hexagon: | TODO |
     |        ia64: | TODO |
-    |   loongarch: | TODO |
+    |   loongarch: |  ok  |
     |        m68k: | TODO |
     |  microblaze: |  ok  |
     |        mips: |  ok  |

arch/loongarch/Kconfig

@@ -94,6 +94,7 @@ config LOONGARCH
 	select HAVE_ASM_MODVERSIONS
 	select HAVE_CONTEXT_TRACKING_USER
 	select HAVE_C_RECORDMCOUNT
+	select HAVE_DEBUG_KMEMLEAK
 	select HAVE_DEBUG_STACKOVERFLOW
 	select HAVE_DMA_CONTIGUOUS
 	select HAVE_DYNAMIC_FTRACE