staging: most: remove shared IRQ request

Since there is no way find out whether the INIC has generated an
interrupt, the I2C interrupt must not be registered as a shared
interrupt.

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