ARM: dts: qcom: msm8974-oneplus-bacon: Add volume keys and hall sensor

Add nodes for the volume buttons and the hall sensor that are found on
the device.

Signed-off-by: Luca Weiss <luca@z3ntu.xyz>
Signed-off-by: Bjorn Andersson <andersson@kernel.org>
Link: https://lore.kernel.org/r/20230122-msm8974-bacon-features-v2-3-06bb83c20a58@z3ntu.xyz