Revert "Fix the latest breakage by defining IREE_TIME_NOW_FN"

This reverts commit 3a0d091ea9323ccfdb115066fee1e93d1751ff63.

Reason for revert: upstream issue fixed and merged.

Change-Id: I21b3840bdeba2acdc4c0f66afc2c739f31400f23

cmake/riscv_iree.cmake

diff --git a/cmake/riscv_iree.cmake b/cmake/riscv_iree.cmake
index 74eea14..3661099 100644
--- a/cmake/riscv_iree.cmake
+++ b/cmake/riscv_iree.cmake
@@ -57,7 +57,6 @@
 set(CMAKE_C_EXTENSIONS OFF)     # Force the usage of _ISOC11_SOURCE
 set(CMAKE_SYSTEM_LIBRARY_PATH "${RISCV_TOOLCHAIN_ROOT}/riscv32-unknown-elf/lib")
 set(RISCV_COMPILER_FLAGS "${RISCV_COMPILER_FLAGS} -menable-experimental-extensions -march=rv32imf_zvl512b_zve32x -mabi=ilp32")
-set(RISCV_COMPILER_FLAGS "${RISCV_COMPILER_FLAGS} -DIREE_TIME_NOW_FN=\"\{ return 0; \}\"")
 
 add_compile_definitions(IREE_PLATFORM_GENERIC)
 

cmake/riscv_iree_gcc.cmake

diff --git a/cmake/riscv_iree_gcc.cmake b/cmake/riscv_iree_gcc.cmake
index 6242e69..fdc9b6e 100644
--- a/cmake/riscv_iree_gcc.cmake
+++ b/cmake/riscv_iree_gcc.cmake
@@ -58,7 +58,6 @@
 set(CMAKE_C_EXTENSIONS OFF)     # Force the usage of _ISOC11_SOURCE
 set(CMAKE_SYSTEM_LIBRARY_PATH "${RISCV_TOOLCHAIN_ROOT}/riscv32-unknown-elf/lib")
 set(RISCV_COMPILER_FLAGS "${RISCV_COMPILER_FLAGS} -march=rv32im -mabi=ilp32")
-set(RISCV_COMPILER_FLAGS "${RISCV_COMPILER_FLAGS} -DIREE_TIME_NOW_FN=\"\{ return 0; \}\"")
 
 add_compile_definitions(IREE_PLATFORM_GENERIC)