DMA: fix printk warning in AMBA PL08x DMA driver

In Rob's recent pull request the patch
	ARM: highbank: select ARCH_DMA_ADDR_T_64BIT for LPAE
promotes dma_addr_t to 64bit, so printk generates a warning about
an incorrect type. Fix this by casting it to u64 and using %llx.
Fixing long lines on the way.

Signed-off-by: Andre Przywara <andre.przywara@linaro.org>
Signed-off-by: Rob Herring <rob.herring@calxeda.com>