kernel: make hwmon-lm75 only depend on kmod-thermal if needed

This fixes commit r42529 and closes #17855.

Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>


git-svn-id: svn://svn.openwrt.org/openwrt/trunk@42531 3c298f89-4303-0410-b956-a3cf2f4a3e73
kernel: add missing config option

Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>


git-svn-id: svn://svn.openwrt.org/openwrt/trunk@42532 3c298f89-4303-0410-b956-a3cf2f4a3e73