Current code handles the CPM1 version of TSA. Connecting and
disconnecting the SCC to/from the TSA consists in handling SICR register
which is CPM1 specific. The connection and disconnection operation in
the QUICC Engine (QE) version are slightly different.

In order to prepare the support for the QE version, clearly identify
SICR register as specific to CPM1 and isolate its handling done in
connect and disconnect functions.
Signed-off-by: Herve Codina <herve.codina@bootlin.com>
Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Link: https://lore.kernel.org/r/20240808071132.149251-13-herve.codina@bootlin.comSigned-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>