[ARM] OMAP3 clock: convert dpll_data.idlest_bit to idlest_mask

Convert struct dpll_data.idlest_bit field to idlest_mask.  Needed since
OMAP2 uses two bits for DPLL IDLEST rather than one.

While here, add the missing idlest_* fields for DPLL3.

linux-omap source commits are 25bab0f176b0a97be18a1b38153f266c3a155784
and b0f7fd17db2aaf8e6e9a2732ae3f4de0874db01c.

Signed-off-by: Paul Walmsley <paul@pwsan.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>