dt-bindings: hwlock: omap: Fix warnings with k3.yaml

Update the AM65x HwSpinlock example to fix couple of warnings
that started showing up after the conversion of K3 bindings to
YAML format in commit 66e06509 ("dt-bindings: arm: ti:
Convert K3 board/soc bindings to DT schema").

 compatible: ['ti,am654'] is not valid under any of the given schemas (Possible causes of the failure):
 compatible: ['ti,am654'] is too short
 compatible:0: 'ti,am654' is not one of ['ti,am654-evm']

Also, fix one of the node names while at this.

Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Suman Anna <s-anna@ti.com>
Link: https://lore.kernel.org/r/20200928225155.12432-1-s-anna@ti.com


Signed-off-by: Rob Herring <robh@kernel.org>