staging: dgap: Simplify set a board type from configration file
Board types need to separate normal command like IO, MEM and so on.
And the board type will come after "board" string in config file normally.
(If it is not, dgap_gettok returns an error with zero)
After that, set a variable of a number which is matched with specific
a board number to "board.type". The dgap_gettok() returns that number so
just set to "board.type" and also "v_type" can be removed.
In case of boards of PCI type are set variables to zero. These can
be removed because "p" as cnode get memory from kzalloc so already
set to zero.