[systemtime] dont init rtc again during set (#28651)

diff --git a/src/platform/Ameba/SystemTimeSupport.cpp b/src/platform/Ameba/SystemTimeSupport.cpp
index 5b7d03b..2fee972 100644
--- a/src/platform/Ameba/SystemTimeSupport.cpp
+++ b/src/platform/Ameba/SystemTimeSupport.cpp
@@ -94,7 +94,6 @@
     struct rtkTimeVal tv;
     tv.tv_sec  = static_cast<uint32_t>(aNewCurTime.count() / UINT64_C(1000000));
     tv.tv_usec = static_cast<uint32_t>(aNewCurTime.count() % UINT64_C(1000000));
-    matter_rtc_init();
     matter_rtc_write(tv.tv_sec);
 
     return CHIP_NO_ERROR;