Add AmlCreatePsdNode() to the AmlLib to generate _PSD objects. _PSD objects allow to describe 'performance control, P-state or CPPC, logical processor dependency', Cf. ACPI 6.5, s8.4.5.5 _PSD (P-State Dependency). Signed-off-by: Pierre Gondois <pierre.gondois@arm.com> Reviewed-by: Sami Mujawar <sami.mujawar@arm.com>