build: alloc space for sched list in the link file

build: alloc space for sched list in the link file

Creates a section to contain scheduler entry pointers that are gathered
together into an array. This will allow, in a follow-on patch, scheduler
entries to be automatically gathered together into the array for
automatic parsing.

Signed-off-by: Jonathan Creekmore <jonathan.creekmore@gmail.com>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>
Reviewed-by: Doug Goldstein <cardoe@cardoe.com>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Acked-by: Ian Campbell <ian.campbell@citrix.com>