thermal: exynos: remove needless therm_trip_[mode,mask]_shift abstractions

reg->therm_trip_mode_shift and reg->therm_trip_mode_mask are
used only in exynos_tmu_control() and accessed only if
pdata->noise_cancel_mode is non-zero.  pdata->noise_cancel
field is not defined on Exynos4210 (also therm_trip_mode_shift
and therm_trip_mode_mask entries are not even assigned in
exynos4210_tmu_registers but they are assigned to identical
values for all other SoC types) so the abstractions are not
needed and can be removed.

There should be no functional changes caused by this patch.

Cc: Amit Daniel Kachhap <amit.daniel@samsung.com>
Cc: Lukasz Majewski <l.majewski@samsung.com>
Cc: Eduardo Valentin <edubezval@gmail.com>
Cc: Zhang Rui <rui.zhang@intel.com>
Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Acked-by: Kyungmin Park <kyungmin.park@samsung.com>
Tested-by: Lukasz Majewski <l.majewski@samsung.com>
Signed-off-by: Eduardo Valentin <edubezval@gmail.com>