regulator: tps65910: add error message in case of failure

Prints error message whenever there is failure on resource
allocation.
Also used dev_* to print messages instead of pr_*

Signed-off-by: Laxman Dewangan <ldewangan@nvidia.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

diff --cc drivers/regulator/tps65910-regulator.c
Simple merge