kernel: mark kmod-thermal menuconfig symbol as hidden to avoid building it on targets with no thermal drivers

Should fix build errors with Linux 3.3/3.6 targets, which use different
kconfig symbols

Signed-off-by: Felix Fietkau <nbd@openwrt.org>

git-svn-id: svn://svn.openwrt.org/openwrt/trunk@38238 3c298f89-4303-0410-b956-a3cf2f4a3e73
kernel: remove old kernel compat code for pcmcia

Signed-off-by: Felix Fietkau <nbd@openwrt.org>

git-svn-id: svn://svn.openwrt.org/openwrt/trunk@38239 3c298f89-4303-0410-b956-a3cf2f4a3e73
kernel: add missing symbols for iio on older kernel versions

Signed-off-by: Felix Fietkau <nbd@openwrt.org>

git-svn-id: svn://svn.openwrt.org/openwrt/trunk@38240 3c298f89-4303-0410-b956-a3cf2f4a3e73