Documentation: Add AMD Zen debugging document

Debugging issues on AMD hardware can be challenging for users without
proper documentation and tools.

Introduce a document that includes techniques for debugging s2idle
issues. It will be expanded for debugging other issues later.

Signed-off-by: Mario Limonciello <mario.limonciello@amd.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Gautham R. Shenoy <gautham.shenoy@amd.com>
Link: https://lore.kernel.org/20250422234830.2840784-2-superm1@kernel.org