Remove sec_reg* helpers as they are not used anymore. These helpers were
error-prone as they mixed u8 with unsigned int and they changed order of
some of parameters (val and mask in sec_reg_update()).

Also the helpers didn't give any way of useful abstraction as they just
called corresponding regmap function.
Signed-off-by: NKrzysztof Kozlowski <k.kozlowski@samsung.com>
Acked-by: NLee Jones <lee.jones@linaro.org>
Signed-off-by: NMark Brown <broonie@linaro.org>