OMAP3 clock: correct module IDLEST bits: SSI; DSS; USBHOST; HSOTGUSB

OMAP3 clock: correct module IDLEST bits: SSI; DSS; USBHOST; HSOTGUSB

Fix two bugs in the OMAP3 clock tree pertaining to the SSI, DSS,
USBHOST, and HSOTGUSB devices.  These devices are both interconnect
initiators and targets.  Without this patch, clk_enable()s on clocks for
these modules can be very high latency (potentially up to ~200
milliseconds) and message such as the following are generated:

    Clock usbhost_48m_fck didn't enable in 100000 tries

Two bugs are fixed by this patch.  First, OMAP hardware only supports
target CM_IDLEST register bits on ES2+ chips and beyond.  ES1 chips
should not wait for these clocks to enable.  So, split the appropriate
clocks into ES1 and ES2+ variants, so that kernels running on ES1
devices won't try to wait.

Second, the current heuristic in omap2_clk_dflt_find_idlest() will
fail for these clocks.  It assumes that the CM_IDLEST bit to wait upon
is the same as the CM_*CLKEN bit, which is false[1].  Fix by
implementing custom clkops .find_idlest function pointers for the
appropriate clocks that return the correct slave IDLEST bit shift.

This was originally fixed in the linux-omap kernel during 2.6.29 in a
slightly different manner[2][3].

In the medium-term future, all of the module IDLEST code will
eventually be moved to the omap_hwmod code.

Problem reported by Jarkko Nikula <jhnikula@gmail.com>:

    http://marc.info/?l=linux-omap&m=124306184903679&w=2

...

1. See for example 34xx TRM Revision P Table 4-213 and 4-217 (for the
   DSS case).

2. http://www.spinics.net/lists/linux-omap/msg05512.html et seq.

3. http://lkml.indiana.edu/hypermail/linux/kernel/0901.3/01498.html

Signed-off-by: Paul Walmsley <paul@pwsan.com>
Cc: Jarkko Nikula <jhnikula@gmail.com>