Compile pflash_cfi01 only once

Push TARGET_WORDS_BIGENDIAN dependency to board level.

Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
diff --git a/default-configs/microblaze-softmmu.mak b/default-configs/microblaze-softmmu.mak
index 4a70526..6c4f4f2 100644
--- a/default-configs/microblaze-softmmu.mak
+++ b/default-configs/microblaze-softmmu.mak
@@ -2,3 +2,4 @@
 
 CONFIG_PTIMER=y
 CONFIG_VIRTIO_PCI=y
+CONFIG_PFLASH_CFI01=y