[otbn] Fix comment in controller

The decoding section doesn't exist in the documentation any more.

Signed-off-by: Philipp Wagner <phw@lowrisc.org>

hw/ip/otbn/rtl/otbn_controller.sv

diff --git a/hw/ip/otbn/rtl/otbn_controller.sv b/hw/ip/otbn/rtl/otbn_controller.sv
index 95144a0..0308caa 100644
--- a/hw/ip/otbn/rtl/otbn_controller.sv
+++ b/hw/ip/otbn/rtl/otbn_controller.sv
@@ -39,7 +39,7 @@
   input  logic                     insn_illegal_i,
   input  logic [ImemAddrWidth-1:0] insn_addr_i,
 
-  // Decoded instruction data, matching the "Decoding" section of the specification.
+  // Decoded instruction data
   input insn_dec_base_t       insn_dec_base_i,
   input insn_dec_bignum_t     insn_dec_bignum_i,
   input insn_dec_shared_t     insn_dec_shared_i,