kernel: config: Enable CONFIG_DMA_CMA which may fix fiq dsm cache coherency issues
See: https://github.com/raspberrypi/linux/issues/575

kernel: config: Add CONFIG_USB_HOS module (option branded GSM modem)
See: https://github.com/raspberrypi/linux/issues/580

tvservice: Allow requesting NTSC frequency variants of hdmi modes
See: http://www.raspberrypi.org/forums/viewtopic.php?f=91&t=75589