DynamicTablesPkg: AmlLib definitions

DynamicTablesPkg: AmlLib definitions

Dynamic AML is a solution to generate Definition Block tables
at runtime. Dynamic AML provides the following techniques for
generating AML tables.
  - AML Fixup
  - AML Codegen
  - AML Fixup + Codegen

AML fixup involves patching small sections of a template AML
code at runtime, while AML Codegen provides APIs to generate
small sections of AML code at runtime. A combination of
Fixup and Codegen can also be used.

AML has a complex grammar. To simplify the generation of
AML tables, Dynamic AML introduces AmlLib that provides a
rich set of APIs for parsing, traversing, fixup, codegen
and serialisation of AML byte code.

This patch introduces the definitions used by AmlLib.

Signed-off-by: Pierre Gondois <pierre.gondois@arm.com>
Signed-off-by: Sami Mujawar <sami.mujawar@arm.com>
Reviewed-by: Alexei Fedorov <Alexei.Fedorov@arm.com>