ARM: multi_v7_defconfig: add tm2-touchkey driver

The Cypress 'touchkey' hardware is available on Exynos4412-based Midas
family boards, so enable the driver for it to increase testing coverage.

Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Link: https://lore.kernel.org/r/20231005111718.1096634-1-m.szyprowski@samsung.com


Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>