Add '-O3' for soft_musl_ldso

Issue:I6778R

Test: Build & Boot devices
Signed-off-by: Nyinchuang <yinchuang@huawei.com>

musl_template.gni

@@ -660,6 +660,7 @@ template("musl_libs") {
       "-fPIC",
       "-ffreestanding",
       "-fno-stack-protector",
+      "-O3",
     ]
     if (is_asan) {
       defines = [