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

arch/arm/configs/multi_v7_defconfig

@@ -315,6 +315,7 @@ CONFIG_KEYBOARD_PXA27x=m
 CONFIG_KEYBOARD_SAMSUNG=m
 CONFIG_KEYBOARD_ST_KEYSCAN=y
 CONFIG_KEYBOARD_SPEAR=y
+CONFIG_KEYBOARD_TM2_TOUCHKEY=m
 CONFIG_KEYBOARD_CROS_EC=m
 CONFIG_MOUSE_PS2_ELANTECH=y
 CONFIG_MOUSE_CYAPA=m