regulator: core: Remove unused get_device_regulator

commit 222cc7b1 (regulator: core: Allow multiple requests of a single supply mapping)
removed the usage of get_device_regulator().

Remove the function definition too amd get rid of the following warning:

drivers/regulator/core.c:112:26: warning: 'get_device_regulator' defined but not used [-Wunused-function]

Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
1 file changed