ADIv5 share DAP command support

ADIv5 share DAP command support

Get rid of needless and undesirable code duplication for
all the DAP commands (resolving a FIXME) ... there's no
need for coreas to have private copies of that stuff.
Stick a pointer to the DAP in "struct arm", letting common
code get to it.

Also rename the "swjdp_info" symbol; just call it "dap".

This is an overall code shrink.

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>