ARM: dts: imx: Add labels to remaining anatop regulators

ARM: dts: imx: Add labels to remaining anatop regulators

Add labels to remaining anatop regulators, so their supplies can be
assigned in board DTs. This is similar to Linux kernel commit
93385546ba369 ("ARM: dts: imx6qdl-sabresd: Assign corresponding power supply for LDOs")
except it does not contain the unrelated sabresd changes.

Signed-off-by: Marek Vasut <marex@denx.de>
Cc: Christoph Niedermaier <cniedermaier@dh-electronics.com>
Cc: Stefano Babic <sbabic@denx.de>
Reviewed-by: Fabio Estevam <festevam@gmail.com>