OMAP: clockdomain: Arch specific funcs for hwsup control of clkdm

Define the following architecture specific funtions for omap2/3/4
.clkdm_allow_idle
.clkdm_deny_idle

Convert the platform-independent framework to call these functions.
Also rename the api's by removing the omap2_ preamble.
Hence call omap2_clkdm_allow_idle as clkdm_allow_idle and
omap2_clkdm_deny_idle as clkdm_deny_idle.

Make the _clkdm_add_autodeps and _clkdm_del_autodeps as non-static
so they can be accessed from OMAP2/3 platform specific code.

Signed-off-by: Rajendra Nayak <rnayak@ti.com>
Signed-off-by: Paul Walmsley <paul@pwsan.com>