[otbn] rename OTBN objdump Python script

In order to be bazelified, which is required in order to build the mask
ROM with bazel, all Python scripts must end in a ".py" extension.

Signed-off-by: Timothy Trippel <ttrippel@google.com>

doc/ug/otbn_sw.md

@@ -61,10 +61,10 @@ hw/ip/otbn/util/otbn_ld.py -o foo foo0.o foo1.o foo2.o
 
 ### Objdump
 
-To disassemble OTBN code, use `otbn-objdump`, which can be found at `hw/ip/otbn/util/otbn-objdump`.
+To disassemble OTBN code, use `otbn_objdump.py`, which can be found at `hw/ip/otbn/util/otbn_objdump.py`.
 This wraps `riscv32-unknown-elf-objdump`, but correctly disassembles OTBN instructions when run with the `-d` flag.
 
 To disassemble the ELF binary linked in the previous section, run
 ```shell
-hw/ip/otbn/util/otbn-objdump -d foo
+hw/ip/otbn/util/otbn_objdump.py -d foo
 ```

hw/ip/otbn/doc/_index.md

@@ -1111,7 +1111,7 @@ The toolchain wraps a RV32 GCC toolchain and supports many of its features.
 The following tools are available:
 * `otbn_as.py`: The OTBN assembler.
 * `otbn_ld.py`: The OTBN linker.
-* `otbn-objdump`: objdump for OTBN.
+* `otbn_objdump.py`: objdump for OTBN.
 
 Other tools from the RV32 toolchain can be used directly, such as objcopy.
 

hw/ip/otbn/util/Makefile

@@ -16,7 +16,7 @@ $(build-dir) $(lint-build-dir):
 	mkdir -p $@
 
 pylibs := $(wildcard shared/*.py docs/*.py)
-pyscripts := yaml_to_doc.py otbn_as.py otbn_ld.py otbn-objdump
+pyscripts := yaml_to_doc.py otbn_as.py otbn_ld.py otbn_objdump.py
 
 lint-stamps := $(foreach s,$(pyscripts),$(lint-build-dir)/$(s).stamp)
 $(lint-build-dir)/%.stamp: % $(pylibs) | $(lint-build-dir)

hw/ip/otbn/util/shared/operand.py

@@ -22,9 +22,9 @@ class OperandType:
         - Encoded value
 
     The string representation is the string that you expect to see in an
-    assembly listing (either fed into otbn_as.py, or generated by otbn-objdump).
-    The encoded value is the non-negative integer value that is encoded in the
-    bits of the instruction.
+    assembly listing (either fed into otbn_as.py, or generated by
+    otbn_objdump.py). The encoded value is the non-negative integer value that
+    is encoded in the bits of the instruction.
 
     The operand value is the notional value of the operand. This might be a
     signed value (represented 2's complement in the encoded value). It might be