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 25bab0f1
and b0f7fd17.
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>