Add ":MathDialect" as a dep of "GPUDialect". Fixes bazel build. (#147376)
Error was:
external/llvm-project/mlir/lib/Dialect/GPU/IR/GPUDialect.cpp:17:10:
fatal error: 'mlir/Dialect/Math/IR/Math.h' file not found
17 | #include "mlir/Dialect/Math/IR/Math.h"
| ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~
1 error generated.