Bump bitmanip submodule for #130

- Fix zip/unzip sail code and descriptions

 On branch master
 Your branch is up-to-date with 'origin/master'.

 Changes to be committed:
	modified:   ../../extern/riscv-bitmanip

 Changes not staged for commit:
	modified:   ../../extern/riscv-gnu-toolchain (modified content)
	modified:   ../../extern/sail-riscv (new commits, untracked content)