sim: dv-sockser: enable for mingw targets too

We have enough functionality from gnulib now to build sockser on
all platforms.

Non-blocking I/O is supported when F_GETFL/F_SETFL are unavailable,
but we can address that in a follow up commit.  This mirrors what
is done in other places in the sim already.

sim/configure

@@ -14439,16 +14439,8 @@ if test "$enable_sim_hardware" = no; then
   sim_hw_cflags="-DWITH_HW=0"
 elif test "$enable_sim_hardware" = yes; then
   sim_hw_cflags="-DWITH_HW=1"
-  # mingw does not support sockser
-  case ${host} in
-    *mingw*) ;;
-    *) # TODO: We don't add dv-sockser to sim_hw as it is not a "real" device
-       # that you instatiate.  Instead, other code will call into it directly.
-       # At some point, we should convert it over.
-       sim_hw_sockser="dv-sockser.o"
-       sim_hw_cflags="$sim_hw_cflags -DHAVE_DV_SOCKSER"
-       ;;
-  esac
+        sim_hw_sockser="dv-sockser.o"
+  sim_hw_cflags="$sim_hw_cflags -DHAVE_DV_SOCKSER"
 else
   as_fn_error $? "unknown argument \"$enable_sim_hardware\"" "$LINENO" 5
 fi