configs: Add a CONFIG_SMC37C669 switch for the "smc37c669-superio" device

This device is not user-creatable and currently only used for the
"alpha" target. So if the user does not want to compile alpha-softmmu,
we should also not compile this device. Add a proper config switch to
be able to compile this more flexibly.

Reviewed-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Thomas Huth <thuth@redhat.com>

default-configs/alpha-softmmu.mak

@@ -19,3 +19,4 @@ CONFIG_IDE_CMD646=y
 CONFIG_I8259=y
 CONFIG_MC146818RTC=y
 CONFIG_ISA_TESTDEV=y
+CONFIG_SMC37C669=y

hw/isa/Makefile.objs

@@ -1,9 +1,10 @@
 common-obj-$(CONFIG_ISA_BUS) += isa-bus.o
-common-obj-$(CONFIG_ISA_BUS) += isa-superio.o smc37c669-superio.o
+common-obj-$(CONFIG_ISA_BUS) += isa-superio.o
 common-obj-$(CONFIG_APM) += apm.o
 common-obj-$(CONFIG_I82378) += i82378.o
 common-obj-$(CONFIG_PC87312) += pc87312.o
 common-obj-$(CONFIG_PIIX4) += piix4.o
 common-obj-$(CONFIG_VT82C686) += vt82c686.o
+common-obj-$(CONFIG_SMC37C669) += smc37c669-superio.o
 
 obj-$(CONFIG_LPC_ICH9) += lpc_ich9.o