staging: most: core: rename members aim* of struct most_channel

This patch renames the struct members "aim0" and "aim0" to "pipe0" and
"pipe1".  It is needed to have a conclusive nomenclature of the struct and
its instances.

Signed-off-by: Christian Gromm <christian.gromm@microchip.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>