[POWERPC] QE: fix invalid pointer usage in ucc_slow_init()

In two places, ucc_slow_init() passes a physical address instead of the
virtual address to functions that were expecting the latter, causing a kernel
panic.  us_info->regs contains the physical address of the UCC register set.
The registers are ioremap'd to kernel space, and the virtual pointers are
stored in us_regs.  The code was using us_info->regs when it should have been
using us_regs.

Signed-off-by: Timur Tabi <timur@freescale.com>
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>