The Bare ETRAX FS board was a fictive machine that I used when
developing the CRIS system emulation. Since we support the
real AXIS-dev88 developer boards, there is no reason to
keep the fictive one around.

This commit also removes the double registration of the axis-dev88
board.
Signed-off-by: NEdgar E. Iglesias <edgar.iglesias@gmail.com>