platforms/arty: add missing pullups on sdcard.

litex_boards/platforms/arty.py

@@ -177,8 +177,8 @@ _sdcard_pmod_io = [
         IOStandard("LVCMOS33"),
     ),
     ("sdcard", 0,
-        Subsignal("data", Pins("F4 E2 D2 D4")),
-        Subsignal("cmd", Pins("D3")),
+        Subsignal("data", Pins("F4 E2 D2 D4"), Misc("PULLUP True")),
+        Subsignal("cmd", Pins("D3"), Misc("PULLUP True")),
         Subsignal("clk", Pins("F3")),
         Subsignal("cd", Pins("H2")),
         Misc("SLEW=FAST"),