Support armcc Compiler (previously known as ARM RealView)

Current toolkit sources does not compile with armcc compiler due to strict structure packing rules. The compiler expect all substructures of a packed structure to be explicitly declared packed as well.

See http://www.keil.com/support/man/docs/armccref/armccref_CJAFJHJD.htm:
The __packed qualifier applies to all members of a structure or union when it is declared using __packed. There is no padding between members, or at the end of the structure. All substructures of a packed structure must be declared using __packed. Integral subfields of an unpacked structure can be packed individually.