[MIPS] Separate Alchemy processor based boards config

Signed-off-by: Yoichi Yuasa <yoichi_yuasa@tripeaks.co.jp>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
diff --git a/arch/mips/configs/db1550_defconfig b/arch/mips/configs/db1550_defconfig
index 5bd3b43..7b35190 100644
--- a/arch/mips/configs/db1550_defconfig
+++ b/arch/mips/configs/db1550_defconfig
@@ -9,6 +9,7 @@
 # Machine selection
 #
 CONFIG_ZONE_DMA=y
+CONFIG_MACH_ALCHEMY=y
 # CONFIG_MIPS_MTX1 is not set
 # CONFIG_MIPS_BOSPORUS is not set
 # CONFIG_MIPS_PB1000 is not set