[CORE] devtree: Add vmm_devtree_find_matching() and vmm_devtree_find_compatible() APIs

Signed-off-by: Anup Patel <anup@brainfault.org>
[ARM] Simplify generic timer initialization

Signed-off-by: Anup Patel <anup@brainfault.org>
Merge remote-tracking branch 'upstream/master'