mtd: nand: Arasan: Fix initialization of controller structure

mtd: nand: Arasan: Fix initialization of controller structure

Make sure that the controller structure is initialized using the
nand_hw_control_init() function. This way the spinlock, waitqueue
elements etc. of the structure will be correctly initialized.

Without this fix the nand driver have been seen stalling, especially
when stress tested.

Signed-off-by: Martin Lund <malu@gomspace.com>
Reviewed-by: Naga Sureshkumar Relli <naga.sureshkumar.relli@xilinx.com>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>