linux: update to linux-3.11-rc2, use linux-3.10 for RPi project, update and add new radeon firmwares

Signed-off-by: Stephan Raue <stephan@openelec.tv>
Mesa: update to Mesa-9.2-20130726

Signed-off-by: Stephan Raue <stephan@openelec.tv>
libdrm: update to libdrm-2.4.46

Signed-off-by: Stephan Raue <stephan@openelec.tv>
projects/Generic_OSS: use fullsize splash with KMS support

Signed-off-by: Stephan Raue <stephan@openelec.tv>
projects/Generic_OSS: enable VDPAU support

Signed-off-by: Stephan Raue <stephan@openelec.tv>