regulator: Use of_node_name_eq for node name comparisons

Convert string compares of DT node names to use of_node_name_eq helper
instead. This removes direct access to the node name pointer.

For instances using of_node_cmp, this has the side effect of now using
case sensitive comparisons. This should not matter for any FDT based
system which all of these are.

Cc: Liam Girdwood <lgirdwood@gmail.com>
Cc: Mark Brown <broonie@kernel.org>
Cc: Support Opensource <support.opensource@diasemi.com>
Cc: Sangbeom Kim <sbkim73@samsung.com>
Cc: Krzysztof Kozlowski <krzk@kernel.org>
Cc: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Cc: linux-samsung-soc@vger.kernel.org
Signed-off-by: Rob Herring <robh@kernel.org>
Acked-by: Adam Thomson <Adam.Thomson.Opensource@diasemi.com>
Signed-off-by: Mark Brown <broonie@kernel.org>