fixed VSSD_PAD connection

diff --git a/sky130/custom/sky130_fd_io/verilog/sky130_ef_io.v b/sky130/custom/sky130_fd_io/verilog/sky130_ef_io.v
index 426e9d0..7462169 100644
--- a/sky130/custom/sky130_fd_io/verilog/sky130_ef_io.v
+++ b/sky130/custom/sky130_fd_io/verilog/sky130_ef_io.v

@@ -1155,8 +1155,8 @@
 	.VSSIO(VSSIO),
 	.VSSD(VSSD),
 	.VSSIO_Q(VSSIO_Q),
-	.G_CORE(VSSD_PAD),
-	.G_PAD(VSSD),
+	.G_CORE(VSSD),
+	.G_PAD(VSSD_PAD),
 	.OGC_LVC(),
 	.BDY2_B2B(VSSIO),
 	.AMUXBUS_A(AMUXBUS_A),