linux: update to linux-3.10.20

Signed-off-by: Stephan Raue <stephan@openelec.tv>
projects/RPi: update RPi kernel patch

Signed-off-by: Stephan Raue <stephan@openelec.tv>
bcm2835-driver: update to bcm2835-driver-b38194c

Signed-off-by: Stephan Raue <stephan@openelec.tv>
bcm2835-bootloader: update to bcm2835-bootloader-b38194c

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