build: Add build instructions for libpal
build: Add build instructions for libpal

Only building base for now.
We need to fix this later.

Signed-off-by: Ola Jeppsson <793f970c52ded1276b9264c742f19d1888cbaf73@adapteva.com>

debug-de-su-ka/pal,RafaelRMA/pal,parallella/pal,parallella/pal,Adamszk/pal3,8l/pal,olajep/pal,Adamszk/pal3,eliteraspberries/pal,mateunho/pal,debug-de-su-ka/pal,mateunho/pal,eliteraspberries/pal,parallella/pal,8l/pal,aolofsson/pal,mateunho/pal,twocs/pal,Adamszk/pal3,twocs/pal,RafaelRMA/pal,eliteraspberries/pal,8l/pal,olajep/pal,olajep/pal,aolofsson/pal,twocs/pal,parallella/pal,8l/pal,debug-de-su-ka/pal,debug-de-su-ka/pal,aolofsson/pal,mateunho/pal,Adamszk/pal3,olajep/pal,twocs/pal,eliteraspberries/pal,aolofsson/pal,eliteraspberries/pal,debug-de-su-ka/pal,RafaelRMA/pal,RafaelRMA/pal,mateunho/pal,parallella/pal