Interface: Update control parameter packing scheme

There are more bits on the way for the control parameter, update
the encoding scheme to prepare for future usage.

The rationale:

- 'type' is a mandatory field, put in LSB to avoid extra shifting.
- Compact other fields to reserve more bits for future usage.

Signed-off-by: Ken Liu <Ken.Liu@arm.com>
Change-Id: Ibc4989b4bed0c1ecf57a026bfad41d65ba61de5b
1 file changed