arm64: dts: mediatek: mt8173-elm: Fix bluetooth node name and reorder

arm64: dts: mediatek: mt8173-elm: Fix bluetooth node name and reorder

Change the node name for Marvell SD8897 SDIO Bluetooth from
`btmrvl@2` to `bluetooth@2` to fix a dtbs_check warning.

While at it, also change the WiFi one from `mwifiex@1" to a
generic "wifi@1" and reorder the nodes so that wifi@1 comes
before bluetooth@2.

Reviewed-by: Chen-Yu Tsai <wenst@chromium.org>
Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>