fbcon: unconditionally initialize cursor blink interval

A sun7i-a20-olinuxino-micro fails to boot when kernel parameter
vt.global_cursor_default=0. The value is copied to vc->vc_deccm
causing the initialization of ops->cur_blink_jiffies to be skipped.
Unconditionally initialize it.

Reported-and-tested-by: Jonathan Liu <net147@gmail.com>
Signed-off-by: Scot Doyle <lkml14@scotdoyle.com>
Acked-by: Pavel Machek <pavel@ucw.cz>
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>