boards: frdm_{kl25z, k64f, kw41z}: Rework programming and debugging doc

Reworks the programming and debugging section in the freedom board
documents to leverage the new debugging guide covering debug probes and
host tools.

These boards support OpenSDA DAPLink and OpenSDA J-Link onboard debug
probes. They can also support an external J-Link probe, but this
requires board modifications (cutting traces) and is therefore not
documented.

Signed-off-by: Maureen Helm <maureen.helm@nxp.com>