clk: omap: introduce clock driver

Parses OMAP clock data from DT and registers those clocks with the clock
framework.  dt_omap_clk_init must be called early during boot for timer
initialization so it is exported and called from the existing clock code
instead of probing like a real driver.

Cc: Benoit Cousson <b-cousson@ti.com>
Cc: Rajendra Nayak <rnayak@ti.com>
Cc: Joel A Fernandes <joelagnel@ti.com>
Cc: Nishanth Menon <nm@ti.com>
Cc: Paul Walmsley <paul@pwsan.com>
Cc: Tony Lindgren <tony@atomide.com>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
ARM: dts: omap4 clock data

This is a first pass at creating a unique node for each clock in the
OMAP4 power, reset and & clock manager (PRCM).  So far I have only
converted mux clocks & fixed-rate clocks, which coexist with the current
clock data in the kernel.  The rest needs to be done but better to
publish early and often to see what others think of this approach.

Cc: Benoit Cousson <b-cousson@ti.com>
Cc: Rajendra Nayak <rnayak@ti.com>
Cc: Joel A Fernandes <joelagnel@ti.com>
Cc: Nishanth Menon <nm@ti.com>
Cc: Paul Walmsley <paul@pwsan.com>
Cc: Tony Lindgren <tony@atomide.com>
Signed-off-by: Mike Turquette <mturquette@linaro.org>
ARM: omap4: register DT clocks & remove old data

Now that some of the OMAP4 PRCM clock data has been converted to a
DeviceTree representation it is no longer needed as static clock data.
Register the DT clocks first, followed by the remaining static clocks.

Cc: Benoit Cousson <b-cousson@ti.com>
Cc: Rajendra Nayak <rnayak@ti.com>
Cc: Joel A Fernandes <joelagnel@ti.com>
Cc: Nishanth Menon <nm@ti.com>
Cc: Paul Walmsley <paul@pwsan.com>
Cc: Tony Lindgren <tony@atomide.com>
Signed-off-by: Mike Turquette <mturquette@linaro.org>