Rename unwinder config symbols to match upstream changes.
Refresh patches.
Update patch that no longer applies: 202-reduce_module_size.patch

Also enable CONFIG_PAGE_TABLE_ISOLATION. This feature was backported
from 4.15 to the 4.14 stable series. It is enabled by default, so enable
it in OpenWrt as well.

Compile-tested on x86/64.
Runtime-tested on x86/64.

Signed-off-by: Stijn Tintel <stijn@linux-ipv6.be>