Some OMAP IP blocks, such as the watchdog timers, cannot be completely
shut down via the standard hwmod shutdown mechanism.  This patch
enables the hwmod data files to supply a pointer to a custom
pre-shutdown function via the struct omap_hwmod_class.pre_shutdown
function pointer.  If the struct omap_hwmod_class.pre_shutdown
function pointer is non-null, the function will be executed before the
existing hwmod shutdown code runs.
Signed-off-by: Paul Walmsley <paul@pwsan.com>
Cc: Benoît Cousson <b-cousson@ti.com>