hw: move I2C controllers to hw/i2c/, configure via default-configs/

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
diff --git a/default-configs/arm-softmmu.mak b/default-configs/arm-softmmu.mak
index a7dd44a..24b0d41 100644
--- a/default-configs/arm-softmmu.mak
+++ b/default-configs/arm-softmmu.mak
@@ -50,6 +50,7 @@
 CONFIG_XGMAC=y
 CONFIG_EXYNOS4=y
 CONFIG_PXA2XX=y
+CONFIG_BITBANG_I2C=y
 CONFIG_FRAMEBUFFER=y
 CONFIG_MARVELL_88W8618=y
 CONFIG_OMAP=y