ARM: dts: qcom: apq8026-samsung-matissewifi: Configure touch keys

Add touch keys which are handled in touchscreen driver.
Use KEY_APPSELECT for the left button because other devices use that
even though downstream kernel uses KEY_RECENT.

Signed-off-by: Matti Lehtimäki <matti.lehtimaki@gmail.com>
Reviewed-by: Konrad Dybcio <konrad.dybcio@linaro.org>
Reviewed-by: Luca Weiss <luca@z3ntu.xyz>
Link: https://lore.kernel.org/r/20231204094649.10094-1-matti.lehtimaki@gmail.com


[bjorn: Wrapped each cell in <>, as requested by Luca]
Signed-off-by: Bjorn Andersson <andersson@kernel.org>