soc: fsl: cpm1: qmc: Rename qmc_chan_command()

soc: fsl: cpm1: qmc: Rename qmc_chan_command()

Current code handles CPM1 version of QMC and qmc_chan_command() is
clearly CPM1 specific.

In order to prepare the support for the QUICC Engine (QE) version,
rename qmc_chan_command() to reflect that point.

Signed-off-by: Herve Codina <herve.codina@bootlin.com>
Reviewed-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Link: https://lore.kernel.org/r/20240808071132.149251-29-herve.codina@bootlin.com
Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>