This change fixes a bug in the SCMI DXE which is observed with the
upcoming release of the SCP firmware.
The PROTOCOL_ID_MASK (0xF) which is used to generate an index in
the ProtocolInitFxns is wrong because protocol ids can be
anywhere in 0x10 - 15 or 0x80 - FF range. This mask generates
the same index for two different protocols e.g. for protocol ids
0x10 and 0x90, which causes duplicate initialization of a protocol
resulting in a failure.
This change removes the use of PROTOCOL_ID_MASK and instead
uses a list of protocol ids and their initialization functions
to identify a supported protocol and initialize it.