fix(xilinx): fix coding style violations

Fix coding style violations and alignments:
- Remove additional newlines in headers
- Remove additional newlines in code
- Add newline to separate variable from the code
- Use the same indentation in platform.mk
- Align function parameters
- Use tabs for indentation in kernel-doc format

Signed-off-by: Michal Simek <michal.simek@xilinx.com>
Change-Id: I0b12804ff63bc19778e8f21041f9accba5b488b9