rtc: interface: Fix coding style violations

Fix issues reported by checkpatch:
  ERROR: open brace '{' following struct go on the same line
  ERROR: "foo* bar" should be "foo *bar"
Additionally adjust alignment of wrapped function arguments.

Signed-off-by: Krzysztof Kozlowski <k.kozlowski.k@gmail.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>