clk: mvebu: ap806: cosmetic improvement

Instead of using &pdev->dev all over the place, introduce a pointer
variable for it.

Signed-off-by: Gregory CLEMENT <gregory.clement@free-electrons.com>
Signed-off-by: Michael Turquette <mturquette@baylibre.com>
Link: lkml.kernel.org/r/5a55e081d96fc6d2a28331b59df90f56d32a9f24.1496239589.git-series.gregory.clement@free-electrons.com