dt-bindings: reserved-memory: ramoops: update ramoops.yaml references

Changeset 89a5bf0f22fd ("dt-bindings: reserved-memory: ramoops: Convert txt bindings to yaml")
renamed: Documentation/devicetree/bindings/reserved-memory/ramoops.txt
to: Documentation/devicetree/bindings/reserved-memory/ramoops.yaml.

Update the cross-references accordingly.

Fixes: 89a5bf0f22fd ("dt-bindings: reserved-memory: ramoops: Convert txt bindings to yaml")
Signed-off-by: Mauro Carvalho Chehab <[e-mail]>
Reviewed-by: David Heidelberg <[e-mail]>
Signed-off-by: Rob Herring <[e-mail]>
Link: https://lore.kernel.org/r/bccd9c[e-mail]

Documentation/admin-guide/ramoops.rst

···
 	mem=128M ramoops.mem_address=0x8000000 ramoops.ecc=1
 
  B. Use Device Tree bindings, as described in
- ``Documentation/devicetree/bindings/reserved-memory/ramoops.txt``.
+ ``Documentation/devicetree/bindings/reserved-memory/ramoops.yaml``.
  For example::
 
 	reserved-memory {

MAINTAINERS

···
 T:	git git://git.kernel.org/pub/scm/linux/kernel/git/kees/linux.git for-next/pstore
 F:	Documentation/admin-guide/ramoops.rst
 F:	Documentation/admin-guide/pstore-blk.rst
-F:	Documentation/devicetree/bindings/reserved-memory/ramoops.txt
+F:	Documentation/devicetree/bindings/reserved-memory/ramoops.yaml
 F:	drivers/acpi/apei/erst.c
 F:	drivers/firmware/efi/efi-pstore.c
 F:	fs/pstore/