docs: simplify DiamondRapids CPU docs

This aligns the first line of the docs with the style used for previous
CPU models, and simplifies the text in the remaining docs.

Reviewed-by: Pierrick Bouvier <pierrick.bouvier@linaro.org>
Reviewed-by: Zhao Liu <zhao1.liu@intel.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
1 file changed