or1k-softmmu.mak: express dependencies with Kconfig

%-softmmu.mak only keep boards and optional device
definitions in Kconfig mode.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

default-configs/or1k-softmmu.mak

@@ -1,6 +1,5 @@
 # Default configuration for or1k-softmmu
 
-CONFIG_SERIAL=y
-CONFIG_OPENCORES_ETH=y
-CONFIG_OMPIC=y
+# Boards:
+#
 CONFIG_OR1K_SIM=y

hw/openrisc/Kconfig

@@ -1,2 +1,5 @@
 config OR1K_SIM
     bool
+    select SERIAL
+    select OPENCORES_ETH
+    select OMPIC