thermal: sun8i: Remove unused variable and unneeded macros

The cp_ft_flag variable is not used after initialization, so delete
it. After that, THS_EFUSE_CP_FT_MASK, THS_EFUSE_CP_FT_BIT and
THS_CALIBRATION_IN_FT are not needed, so delete them.

Signed-off-by: Yangtao Li <tiny.windzz@gmail.com>
Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org>
Link: https://lore.kernel.org/r/20200112180925.23705-1-tiny.windzz@gmail.com