ARM: s3c: remove a leftover hwmon-s3c.h header file

The last user of defined structures s3c_hwmon_pdata and s3c_hwmon_chcfg
was removed in commit 0d297df ("ARM: s3c: simplify platform code"),
thus the platform data header file itself can be removed also.

Signed-off-by: Vladimir Zapolskiy <vz@mleia.com>
Link: https://patch.msgid.link/20260112211554.3755188-1-vz@mleia.com
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>

Author: vzapolskiy