projects/Cuboxi/linux: build SGTL5000 codec statically in kernel, cleanup kernel config, add CONFIG_FB_MXC_LDB

Signed-off-by: Stephan Raue <stephan@openelec.tv>
ppp: disable PPP_FILTER support, this fixes building if /usr/include/pcap-bpf.h is found, todo: move libpcap to unofficial

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