doc: ti: k3: add language for code-block directive

doc: ti: k3: add language for code-block directive

The code-block directive supports the optional language property which
enables syntax highlighting for the block[1].

This patch adds the relevant language property for code-blocks in k3
docs.

[1]:
https://www.sphinx-doc.org/en/master/usage/restructuredtext/directives.html#directive-code-block

Signed-off-by: Anshul Dalal <anshuld@ti.com>