Reduce WB_N to 7 as for 8 it stopped instantiating CPU.

Signed-off-by: Jakub Duchniewicz <j.duchniewicz@gmail.com>

projects/riscv_usb/rtl/top.v

@@ -50,7 +50,7 @@ module top (
 );
 
 	localparam integer SPRAM_AW = 14; /* 14 => 64k, 15 => 128k */
-	localparam integer WB_N  =  8; // TODO: Reduce
+	localparam integer WB_N  =  7; // TODO: Reduce
 
 	localparam integer WB_DW = 32;
 	localparam integer WB_AW = 16;