Invert reset button, so that board is reset when btn is pushed.

Signed-off-by: Tim Callahan <tcal@google.com>

litex_boards/targets/digilent_basys3.py

@@ -29,7 +29,7 @@ class _CRG(Module):
         self.clock_domains.cd_vga       = ClockDomain(reset_less=True)
 
         self.submodules.pll = pll = S7MMCM(speedgrade=-1)
-        self.comb += pll.reset.eq(~platform.request("user_btnc") | self.rst)
+        self.comb += pll.reset.eq(platform.request("user_btnc") | self.rst)
 
         pll.register_clkin(platform.request("clk100"), 100e6)
         pll.create_clkout(self.cd_sys, sys_clk_freq)