The new OMAP4 IPs introduced a new idle mode named smart-idle with wakeup.

This new idlemode replaces the enawakeup for the new IPs but seems to
coexist as well for some legacy IPs (UART, GPIO, MCSPI...)

Add the new SIDLE_SMART_WKUP flag to mark the IPs that support this
capability.
The omap_hwmod_44xx_data.c will have to be updated to add this new flag.

Enable this new mode when applicable in _enable_wakeup, _enable_sysc and
_idle_sysc.

Signed-off-by: Benoit Cousson <b-cousson@ti.com>
Tested-by: Sebastien Guiriec <s-guiriec@ti.com>
Signed-off-by: Paul Walmsley <paul@pwsan.com>
Cc: Kevin Hilman <khilman@deeprootsystems.com>
Cc: Rajendra Nayak <rnayak@ti.com>