doc: Update mentions of README.fdt-control Update documents 'README.fdt-control' reference to replacement 'control.rst': doc/arch/nios2.rst dts/Makefile Also convert some adjacent pathname mentions to rST links where applicable Fixes: 3e9fddfc4f14 "doc: Move devicetree control doc to rST" Signed-off-by: E Shattow <e@freeshell.de>