kernel: bump to 3.10.26

kernel: config: Remove CONFIG_RTC_HCTOSYS
See: https://github.com/raspberrypi/linux/issues/163

firmware: New night node parameters
See: http://www.raspberrypi.org/phpBB3/viewtopic.php?f=43&t=62364&start=175#p483816

firmware: vdec3: Fix for gray blocks near start of streams
See: http://forum.xbmc.org/showthread.php?tid=181677