nrf51: Update known devices table.

nrf51: Update known devices table.

Added new entries to the nrf51_known_devices_table array. New entries
are documented in the "nRF51 Series Compatability Matrix V1.0" found on
the Nordic Semi web site. Reordered entries to match the order found in
the document.

Also added an entry for an undocumented hwid discovered while flashing
the PCA10031 and PCA10028 dev boards.

Change-Id: Icca7da103d437dc28e651f27ab937fe953b9aac9
Signed-off-by: Theodore A. Roth <troth@openavr.org>
Reviewed-on: http://openocd.zylin.com/2514
Tested-by: jenkins
Reviewed-by: Paul Fertser <fercerpav@gmail.com>