regulator: cpcap: Constify cpcap_regulator_ops

regulator: cpcap: Constify cpcap_regulator_ops

cpcap_regulator_ops is not modified and can be made const to allow the
compiler to put it in read-only memory.

Before:
   text    data     bss     dec     hex filename
  14472     236       0   14708    3974 drivers/regulator/cpcap-regulator.o

After:
   text    data     bss     dec     hex filename
  14604     104       0   14708    3974 drivers/regulator/cpcap-regulator.o

Signed-off-by: Rikard Falkeborn <rikard.falkeborn@gmail.com>
Link: https://lore.kernel.org/r/20200617223247.25566-3-rikard.falkeborn@gmail.com
Signed-off-by: Mark Brown <broonie@kernel.org>