Add "reset watermark" handler

Verify: pass TC-DGSW-2.3

Signed-off-by: Chin-Ran Lo <chin-ran.lo@nxp.com>

Author: crlonxp

src/platform/nxp/mw320/DiagnosticDataProviderImpl.cpp

@@ -93,6 +93,17 @@ CHIP_ERROR DiagnosticDataProviderImpl::GetCurrentHeapHighWatermark(uint64_t & cu
     return CHIP_NO_ERROR;
 }
 
+CHIP_ERROR DiagnosticDataProviderImpl::ResetWatermarks()
+{
+    // If implemented, the server SHALL set the value of the CurrentHeapHighWatermark attribute to the
+    // value of the CurrentHeapUsed.
+
+    // On Linux, the write operation is non-op since we always rely on the mallinfo system
+    // function to get the current heap memory.
+
+    return CHIP_NO_ERROR;
+}
+
 CHIP_ERROR DiagnosticDataProviderImpl::GetRebootCount(uint16_t & rebootCount)
 {
     uint32_t count = 0;

src/platform/nxp/mw320/DiagnosticDataProviderImpl.h

@@ -39,9 +39,11 @@ class DiagnosticDataProviderImpl : public DiagnosticDataProvider
 
     // ===== Methods that implement the PlatformManager abstract interface.
 
+    bool SupportsWatermarks() override { return true; }
     CHIP_ERROR GetCurrentHeapFree(uint64_t & currentHeapFree) override;
     CHIP_ERROR GetCurrentHeapUsed(uint64_t & currentHeapUsed) override;
     CHIP_ERROR GetCurrentHeapHighWatermark(uint64_t & currentHeapHighWatermark) override;
+    CHIP_ERROR ResetWatermarks() override;
 
     CHIP_ERROR GetRebootCount(uint16_t & rebootCount) override;
     CHIP_ERROR GetUpTime(uint64_t & upTime) override;