b43: Remove "shm" and "ucode_regs" debugfs files

We don't need these two dump-files anymore, as we can easily do this
in userspace now.
Use b43-fwdump from the b43-tools repository to dump microcode registers.
Use "b43-fwdump -s" to dump SHM (or use -S to do a binary dump)

Signed-off-by: Michael Buesch <mb@bu3sch.de>
Signed-off-by: John W. Linville <linville@tuxdriver.com>