[prim] Packer to remove unused parameter.

Old packer used MaxW to create internal storage. Newer version does not
use MaxW paramter. Removed it.

Signed-off-by: Eunchan Kim <eunchan@opentitan.org>
diff --git a/hw/ip/prim/rtl/prim_packer.sv b/hw/ip/prim/rtl/prim_packer.sv
index ceb7bbc..676d2b6 100644
--- a/hw/ip/prim/rtl/prim_packer.sv
+++ b/hw/ip/prim/rtl/prim_packer.sv
@@ -30,7 +30,6 @@
   localparam int Width = InW + OutW; // storage width
   localparam int ConcatW = Width + InW; // Input concatenated width
   localparam int PtrW = $clog2(ConcatW+1);
-  localparam int MaxW = (InW > OutW) ? InW : OutW;
   localparam int IdxW = $clog2(InW) + ~|$clog2(InW);
 
   logic valid_next, ready_next;