ARM: OMAP2/3: Add idle_st bits for ST_32KSYNC timer to prcm-common header

Add missing idle_st bit for 32k-sync timer into the prcm-common
header file, required for hwmod data.

Signed-off-by: Vaibhav Hiremath <hvaibhav@ti.com>
Reviewed-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Cc: Felipe Balbi <balbi@ti.com>
Cc: Benoit Cousson <b-cousson@ti.com>
Cc: Tony Lindgren <tony@atomide.com>
Cc: Paul Walmsley <paul@pwsan.com>
Cc: Kevin Hilman <khilman@ti.com>
Signed-off-by: Paul Walmsley <paul@pwsan.com>