OMAP4: clock: Add dummy clock nodes for interface clocks

On OMAP4 platform the iclk control is completly under hardware control
and no software control is available.

This difference w.r.t previous OMAP's needs all the common driver
accross OMAP's , cpu_is_xxxx() checks. To avoid poulluting the
drivers dummy clock nodes are created (The autogeneration
script has been updated accordingly).

Signed-off-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Signed-off-by: Rajendra Nayak <rnayak@ti.com>
Signed-off-by: Benoit Cousson <b-cousson@ti.com>
[paul@pwsan.com: made OMAP1 dummy_ck common and edited patch to reuse that]
Signed-off-by: Paul Walmsley <paul@pwsan.com>