msm: clock-generic: Add support for recursive set parent to mux_clk

When there are a bunch of nested muxes and a consumer calls
clk_set_parent() on the top level mux, it's possible that the consumer
doesn't care if the new parent is an immediate parent to the top level mux
and just wants the output from the new parent. So, recursively search for
the new parent (if recursive set parent is enabled for the mux) and get the
output of the new parent even if it has to go through multiple levels of
consecutive muxes.

Change-Id: Ibf76f11587e7c00fe1d34ce956e5a73c8db73e65
Signed-off-by: Saravana Kannan <skannan@codeaurora.org>