thermal/drivers/sprd: Fix temperature clamping in sprd_thm_temp_to_rawdata

thermal/drivers/sprd: Fix temperature clamping in sprd_thm_temp_to_rawdata

The temperature was never clamped to SPRD_THM_TEMP_LOW or
SPRD_THM_TEMP_HIGH because the return value of clamp() was not used. Fix
this by assigning the clamped value to 'temp'.

Casting SPRD_THM_TEMP_LOW and SPRD_THM_TEMP_HIGH to int is also
redundant and can be removed.

Fixes: 554fdbaf19b1 ("thermal: sprd: Add Spreadtrum thermal driver support")
Signed-off-by: Thorsten Blum <thorsten.blum@linux.dev>
Signed-off-by: Daniel Lezcano <daniel.lezcano@kernel.org>
Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: stable@vger.kernel.org
Link: https://patch.msgid.link/20260307102422.306055-1-thorsten.blum@linux.dev