MIPS: Alchemy: rename directory

It's more than the au1000 these days.

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig
index 00a23a1..c15416c 100644
--- a/arch/mips/Kconfig
+++ b/arch/mips/Kconfig
@@ -598,7 +598,7 @@
 
 endchoice
 
-source "arch/mips/au1000/Kconfig"
+source "arch/mips/alchemy/Kconfig"
 source "arch/mips/basler/excite/Kconfig"
 source "arch/mips/jazz/Kconfig"
 source "arch/mips/lasat/Kconfig"