dfu-prefix, dfu-suffix, dfu-util, openocd: no 64-bit linux version

[terrillmoore]

These tools are shipped only in 32-bit linux form. Unfortunately, any build uses dfu-suffix, and that in turn triggers a problem on Travis CI. The solution is probably to track down the original tools and provide 64-bit forms; or else fix the builds not to use dfu-suffix.

Also, this will cause weird headaches for beginning users who haven't installed 32-bit support on their 64-bit linux.

openocd can probably be removed from the build, as it seems not to be used.

A typical failure message is (from this build)

$ arduino --verify --board $(_stm32l0opts '' us915  ) $THISLIB/examples/header_test/header_test.ino
Picked up JAVA_TOOL_OPTIONS: 
Picked up _JAVA_OPTIONS: -Xmx2048m -Xms512m
Loading configuration...
Initializing packages...
Preparing boards...
Verifying...
fork/exec /home/travis/.arduino15/packages/mcci/hardware/stm32/1.1.0/tools/linux//dfu-suffix: no such file or directory

The command "arduino --verify --board $(_stm32l0opts '' au921  ) $THISLIB/examples/header_test/header_test.ino" exited with 1.

See mcci-catena/arduino-lorawan#45 for an example of the gyrations this causes.

[terrillmoore]

@svelmurugan92 @dhineshkumarmcci can you please check the upstream branch of the BSP and see if they have 64-bit linux tools for DFU? if so, we need to add them. That work needs to be done and tested on Linux 64-bit; I can do it if you can find the tools.