Settings: correct kernel version display for all toolchains

The current regex assumes only one set of parethesis eg. (GCC)
many toolchains including linaro and googles gcc-4.6 eabi contain
two sets of them eg. (prerelease) (GCC) which borks the regex

This patch makes the regex less specific so versions built with any toolchain
should be displayed correctly.

Change-Id: I40de6b729c252e61953dfe1860a660a0e5b06b3c