gateware: Minor syntax fixes

Theses syntax error are ignored by yosys but trying synopsys, it is more
strict, so fix them. Right thing to do anyway ...

Signed-off-by: Sylvain Munaut <tnt@246tNt.com>
diff --git a/gateware/common/rtl/soc_base.v b/gateware/common/rtl/soc_base.v
index 7c5c407..34fdc06 100644
--- a/gateware/common/rtl/soc_base.v
+++ b/gateware/common/rtl/soc_base.v
@@ -261,7 +261,7 @@
 	// Boot memory - 1k
 	soc_bram #(
 		.AW(8),
-		.INIT_FILE("boot.hex"),
+		.INIT_FILE("boot.hex")
 	) bram_I (
 		.addr (bram_addr),
 		.rdata(bram_rdata),