[MLIR] Apply clang-tidy fixes for misc-use-internal-linkage in TosaOps.cpp (NFC)

GitOrigin-RevId: 89508c359249b80a9a0bf678c2c4ef5421fe791d
diff --git a/lib/Dialect/Tosa/IR/TosaOps.cpp b/lib/Dialect/Tosa/IR/TosaOps.cpp
index 87bed81..b4c87a3 100644
--- a/lib/Dialect/Tosa/IR/TosaOps.cpp
+++ b/lib/Dialect/Tosa/IR/TosaOps.cpp
@@ -512,20 +512,20 @@
 // Tosa utilities.
 //===----------------------------------------------------------------------===//
 
-std::optional<int64_t> idivCheck(const int64_t lhs, const int64_t rhs) {
+static std::optional<int64_t> idivCheck(const int64_t lhs, const int64_t rhs) {
   if (lhs % rhs != 0)
     return std::nullopt;
   return lhs / rhs;
 }
 
-Type getStorageElementTypeOrSelf(Type type) {
+static Type getStorageElementTypeOrSelf(Type type) {
   auto srcType = getElementTypeOrSelf(type);
   if (auto quantType = llvm::dyn_cast<mlir::quant::QuantizedType>(srcType))
     srcType = quantType.getStorageType();
   return srcType;
 }
 
-Type getStorageElementTypeOrSelf(Value value) {
+static Type getStorageElementTypeOrSelf(Value value) {
   return getStorageElementTypeOrSelf(value.getType());
 }