ARM: dts: qcom: apq8064 merge hw splinlock into corresponding syscon device

ARM: dts: qcom: apq8064 merge hw splinlock into corresponding syscon device

Follow up the expected way of describing the SFPB hwspinlock and merge
hwspinlock node into corresponding syscon node, fixing several dt-schema
warnings.

Fixes: 24a9baf933dc ("ARM: dts: qcom: apq8064: Add hwmutex and SMEM nodes")
Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>
Reviewed-by: Konrad Dybcio <konrad.dybcio@oss.qualcomm.com>
Link: https://lore.kernel.org/r/20250318-fix-nexus-4-v2-7-bcedd1406790@oss.qualcomm.com
Signed-off-by: Bjorn Andersson <andersson@kernel.org>