Move target related code into it's own directory

[theotherjimmy]

This should make it easier to navigate the code base, and reduces
technical debt.

Testing

• /morph test : to verify that I did not break post-bulid scripts

[theotherjimmy]

/morph test

[theotherjimmy]

@0xc0170 After this is merged, we should push partners to put there target code here. I moved all of it that's currently in the tools. I just want new target code to go here too.

[theotherjimmy]

@c1728p9 Part of the technical debt I was talking about earlier.

[theotherjimmy]

@bridadan Any more tests to run?

[theotherjimmy]

@screamerbg Could we mention the owners of the moved target code in this PR to get their input on the move? in particular this PR affects the location of LPC and NCS target-specific files.

[mbed-bot]

Result: SUCCESS

Your command has finished executing! Here's what you wrote!

/morph test

Output

mbed Build Number: 1720

All builds and test passed!

[bulislaw]

Looks good, thanks for notifying Realtek.

[0xc0170]

@0xc0170 After this is merged, we should push partners to put there target code here. I moved all of it that's currently in the tools. I just want new target code to go here too.

+1, will do

[bridadan]

Loving the changes! We should run the mbed 2 bot too just to double check

[bridadan]

@mbed-bot: TEST

HOST_OSES=ALL
BUILD_TOOLCHAINS=ALL
TARGETS=ALL

[screamerbg]

Like it! LGTM

[mbed-bot]

[Build 1314]
FAILURE: Something went wrong when building and testing.

[bridadan]

This is failing due to the issue I mention here: #4021 (comment)

We'll need help from Nordic to fix the issue, stay tuned over on #4021

[0xc0170]

@mbed-bot: TEST

HOST_OSES=ALL
BUILD_TOOLCHAINS=ALL
TARGETS=ALL

[mbed-bot]

[Build 1325]
SUCCESS: Building succeeded and tests were run! Be sure to check the test results