firmware: ti_sci: extend clock identifiers from u8 to u32

firmware: ti_sci: extend clock identifiers from u8 to u32

Future SoCs are going to have more than 255 device clocks in certain cases,
and thus the API must be extended to support this. The support is done in
backwards compatible extension, in which the new u32 clock identifier
fields are only used if the existing u8 size clock identifier is set as
255. In all the other cases, the existing u8 clock identifier is used. As
the size of the messages sent / received is not verified for existing
devices / old firmware, increasing the size of the messages from the end
is also fine. Due to this reason, depending on ABI version isn't necessary
either.

Acked-by: Santosh Shilimkar <ssantosh@kernel.org>
Signed-off-by: Tero Kristo <t-kristo@ti.com>