regulator: tps65910: Fix array access out of bounds bug

For tps65910, the number of regulator is 13. ( ARRAY_SIZE(tps65910_regs) is 13)
For tps65911, the number of regulator is 12. ( ARRAY_SIZE(tps65911_regs) is 12)
If we are using this driver for tps65911,
we hit array access out of bounds bug in tps65910_probe() because
current implementation always assume the number of regulator is 13 and
thus it will access tps65911_regs[12].

Fix it by setting correct num_regulators for both chips in tps65910_probe(),
and allocated neccessay memory accordingly.

Signed-off-by: Axel Lin <axel.lin@gmail.com>
Acked-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Liam Girdwood <lrg@slimlogic.co.uk>