Using the devm_* managed resources the pca driver can be simplified
and cut down on boilerplate code.

[gcl: fixed a inccorect reference to a removed label, "goto fail_out"
became "return ret"]
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>
Signed-off-by: NGregory CLEMENT <gregory.clement@free-electrons.com>
Signed-off-by: NLinus Walleij <linus.walleij@linaro.org>