LatticeMico32 target support

This patch adds support for the LatticeMico32 softcore processor by Lattice
Semiconductor.

Signed-off-by: Michael Walle <michael@walle.cc>
Signed-off-by: Edgar E. Iglesias <edgar.iglesias@gmail.com>
diff --git a/arch_init.c b/arch_init.c
index cc56f0f..0c09f91 100644
--- a/arch_init.c
+++ b/arch_init.c
@@ -64,6 +64,8 @@
 #define QEMU_ARCH QEMU_ARCH_I386
 #elif defined(TARGET_M68K)
 #define QEMU_ARCH QEMU_ARCH_M68K
+#elif defined(TARGET_LM32)
+#define QEMU_ARCH QEMU_ARCH_LM32
 #elif defined(TARGET_MICROBLAZE)
 #define QEMU_ARCH QEMU_ARCH_MICROBLAZE
 #elif defined(TARGET_MIPS)