bindings: input: qcom-hv-haptics: add "qcom,wf-fifo-preload" property

Add "qcom,wf-fifo-preload" property for FIFO effects to be able to
preload into pattern memory during boot up.

Change-Id: Icb11c5efc7039abe290d024288d964c651b21d4e

bindings/input/qcom-hv-haptics.txt

@@ -232,6 +232,19 @@ different vibration effects:
 		in "qcom,wf-fifo-data".
 		See definition at: include/dt-bindings/input/qcom,hv-haptics.h
 
+- qcom,wf-fifo-preload:
+  Usage:	optional
+  Value type:	<bool>
+  Definition:	Specifies if the FIFO effect data should be preloaded into
+		pattern memory during boot up. In HAP525_HV module, there are
+		4 pattern memory partitions with configurable size and each
+		partition can be used for preloading one FIFO effect. The total
+		FIFO memory space is 2K bytes and 640 bytes space is reserved
+		for FIFO streaming mode which needs to load the FIFO data at
+		runtime, the rest can be all used for pattern memory partitions.
+		This feature is only available for HAP525_HV haptics module
+		that is present on PMICs like PM8550B.
+
 - qcom,wf-brake-mode:
   Usage:	optional
   Value type:	<u32>