Remove patch

[gendx]

Fixes #58. This synchronizes with upstream Tock to remove the patch added in #60.

• Tests pass
• Appropriate changes to README are included in PR

[gendx]

There's something weird happening on my desktop.

My guess is that because my build folder is longer than on Travis, the binary is bigger. Indeed, due to Rust including debug paths in binaries, the longer the folder, the larger the binary.

$ strings boards/nordic/nrf52840dk/target/thumbv7em-none-eabi/release/nrf52840dk | grep <my build folder> | wc -l
579

This means that I reach the limit of 128K currently set in the layout.ld, but not Travis and GitHub workflows (yet).

We should be able to increase the limit to 192K (the prog section starts at address 0x00030000), but I want to make sure that regressions are caught by our CI.

---

On Travis:

   Compiling nrf52dk_base v0.1.0 (/home/travis/build/google/OpenSK/third_party/tock/boards/nordic/nrf52dk_base)
    Finished release [optimized + debuginfo] target(s) in 26.07s
   text	   data	    bss	    dec	    hex	filename
 128512	   1720	 260424	 390656	  5f600	target/thumbv7em-none-eabi/release/nrf52840dk

=> text + data = 130232 = 0x1FCB8

For me the text section takes 1024 more bytes:

    Finished release [optimized + debuginfo] target(s) in 0.02s
   text	   data	    bss	    dec	    hex	filename
 129536	   1720	 260424	 391680	  5fa00	target/thumbv7em-none-eabi/release/nrf52840dk

=> text + data = 131256 = 0x200B8

Edit: on GitHub workflow with a long directory name:

   Compiling nrf52dk_base v0.1.0 (/home/runner/work/OpenSK/OpenSK/this-is-a-long-build-directory-0123456789abcdefghijklmnopqrstuvwxyz/third_party/tock/boards/nordic/nrf52dk_base)
    Finished release [optimized + debuginfo] target(s) in 20.30s
   text	   data	    bss	    dec	    hex	filename
 131072	   1720	 260424	 393216	  60000	target/thumbv7em-none-eabi/release/nrf52840dk

=> text + data = 132792 = 0x206B8

[ia0]

Sounds good to me to use 192K. Also note that we don't use 0x30000-0x40000. So we could also push that limit if needed.

[gendx]

Sounds good to me to use 192K. Also note that we don't use 0x30000-0x40000. So we could also push that limit if needed.

That's good to know. Although I don't expect reaching the next limit soon. We could also tune the board configuration to remove all the drivers that we don't use, which would definitely free up some space but also be one more patch to maintain.

[gendx]

I also tested the app on the nRF52840-DK. Works.

$ ./deploy.py os --board nrf52840_dk
$ ./deploy.py app --opensk
$ ./deploy.py app --panic-console --debug --opensk

[gendx]

Removed the path rules in the new workflow, to keep this pull-request focused on removing the patch.

I don't think the build_boards is slow enough to justify specialized path rules, but if so we can do that in a separate pull-request.