pinctrl: fix a memleak when freeing maps

We forgot to free the node itself when free:ing a map.

Reported-by: xulinuxkernel <xulinuxkernel@gmail.com>
Reviewed-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Git-commit: db6c2c69c27f2c4fd1e2a1c6b0b1119b1e885f8a
Git-repo: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git


Change-Id: Icb8d5a33e7e869b2299b06d77e91469df5947b06
Signed-off-by: Hanumant Singh <hanumant@codeaurora.org>