clk: track the orphan status of clocks and their children

While children of orphan clocks are not carried in the orphan-list itself,
they're nevertheless orphans in their own right as they also don't have an
input-rate available. To ease tracking if a clock is an orphan or has an
orphan in its parent path introduce an orphan field into struct clk and
update it and the fields in child-clocks when a clock gets added or removed
from the orphan-list.

Suggested-by: Stephen Boyd <sboyd@codeaurora.org>
Signed-off-by: Heiko Stuebner <heiko@sntech.de>
Cc: Boris Brezillon <boris.brezillon@free-electrons.com>
Cc: Alex Elder <elder@linaro.org>
Cc: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Cc: Stephen Warren <swarren@wwwdotorg.org>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: kernel@pengutronix.de
Cc: Zhangfei Gao <zhangfei.gao@linaro.org>
Cc: Santosh Shilimkar <ssantosh@kernel.org>
Cc: Chao Xie <chao.xie@marvell.com>
Cc: Jason Cooper <jason@lakedaemon.net>
Cc: Stefan Wahren <stefan.wahren@i2se.com>
Cc: Andrew Bresticker <abrestic@chromium.org>
Cc: Robert Jarzmik <robert.jarzmik@free.fr>
Cc: Georgi Djakov <georgi.djakov@linaro.org>
Cc: Sylwester Nawrocki <s.nawrocki@samsung.com>
Cc: Geert Uytterhoeven <geert+renesas@glider.be>
Cc: Barry Song <baohua@kernel.org>
Cc: Dinh Nguyen <dinguyen@opensource.altera.com>
Cc: Viresh Kumar <viresh.linux@gmail.com>
Cc: Gabriel FERNANDEZ <gabriel.fernandez@st.com>
Cc: emilio@elopez.com.ar
Cc: Peter De Schrijver <pdeschrijver@nvidia.com>
Cc: Tero Kristo <t-kristo@ti.com>
Cc: Ulf Hansson <ulf.hansson@linaro.org>
Cc: Pawel Moll <pawel.moll@arm.com>
Cc: Michal Simek <michal.simek@xilinx.com>
[sboyd@codeaurora.org: s/clk/core/ in new function]
Signed-off-by: Stephen Boyd <sboyd@codeaurora.org>