kernel: bump to 3.12.21

kernel: config: Add CONFIG_HID_XINMO
See: https://github.com/raspberrypi/linux/issues/609

firmware: audio_render/audio_mixer: Support planar formats

firmware: bootcode: increase sdcard timeout to avoid observed boot failure under certain conditions

firmware: deinterlace_double - fix image locking
See: https://github.com/raspberrypi/firmware/issues/181

firmware: Convert image_fx for use with MMAL and MMAL_ENCODING_OPAQUE
See: https://github.com/raspberrypi/firmware/issues/278

firmware: RIL Camera: fix handling for stride>required stride
See: https://github.com/raspberrypi/userland/issues/177
firmware: audio_mixer: Fix issue with planar audio when output channels needed expansion

hdmi: Include requested mode and allow hdmi drive when edid fails
See: http://openelec.tv/forum/124-raspberry-pi/71491-4-0-4-passthru-audio-50-working-chance

tvservice: More accurate description of standby message
See: https://github.com/raspberrypi/firmware/issues/286
display: Relax some conditions to allow higher resolution displays
See: http://www.raspberrypi.org/forums/viewtopic.php?f=38&t=79330
kernel: Bump to 3.12.22

kernel: config: Add CONFIG_IPV6_PRIVACY
See: https://github.com/raspberrypi/linux/issues/612

kernel: vchiq: Include SIGTRAP in list of signals not-masked by vchiq to allow gdb to work
See: http://www.raspberrypi.org/forums/viewtopic.php?f=67&t=76377

firmware: deinterlace: Improve 1080i deinterlace
Also deinterlaces chroma. Bilinear interpolate duplicated pixels
kernel: vmstat: Workaround for issue where dirty page count goes negative
See: https://github.com/raspberrypi/linux/issues/617

kernel: vchiq: Include SIGSTOP and SIGCONT in list of signals not-masked by vchiq to allow gdb to work
See: http://www.raspberrypi.org/forums/viewtopic.php?f=67&t=76377

firmware: gencmd: Add queries for malloc and reloc free memory
See: http://forum.stmlabs.com/showthread.php?tid=13737&pid=104854#pid104854

firmware: display: Add support for 32bpp palettes
See: https://github.com/raspberrypi/firmware/issues/276

firmware: Alterations to support camera DRC.  (Dynamic range compression)
See: http://www.raspberrypi.org/forums/viewtopic.php?f=43&t=79622

userland: egl: Call khrn_init_options so env vars like V3D_DOUBLE_BUFFER are respected

userland: hello_fft: Add qasm source files