staging: fsl-mc: fixed bug in uninitialized root dprc irq count

When initializing the object attributes for the root dprc, the
irq_count was uninitialized. Initialize it to 1.

Signed-off-by: J. German Rivera <German.Rivera@freescale.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>