Remove flags and elf target

Unnecessary compile flags are removed.
The explicit ELF target is removed.

cmake/gcc_stm32.cmake

@@ -45,9 +45,9 @@ SET(CMAKE_OBJCOPY ${TOOLCHAIN_BIN_DIR}/${TARGET_TRIPLET}-objcopy CACHE INTERNAL
 SET(CMAKE_OBJDUMP ${TOOLCHAIN_BIN_DIR}/${TARGET_TRIPLET}-objdump CACHE INTERNAL "objdump tool")
 SET(CMAKE_DEBUGER ${TOOLCHAIN_BIN_DIR}/${TARGET_TRIPLET}-gdb CACHE INTERNAL "debuger")
 
-SET(CMAKE_C_FLAGS_DEBUG "--specs=rdimon.specs -lgcc -lc -lm -lrdimon -lnosys -Og -g" CACHE INTERNAL "c compiler flags debug")
-SET(CMAKE_CXX_FLAGS_DEBUG "--specs=rdimon.specs -lgcc -lc -lm -lrdimon -Og -g" CACHE INTERNAL "cxx compiler flags debug")
-SET(CMAKE_ASM_FLAGS_DEBUG "-g -gstabs+" CACHE INTERNAL "asm compiler flags debug")
+SET(CMAKE_C_FLAGS_DEBUG "-Og -g" CACHE INTERNAL "c compiler flags debug")
+SET(CMAKE_CXX_FLAGS_DEBUG "-Og -g" CACHE INTERNAL "cxx compiler flags debug")
+SET(CMAKE_ASM_FLAGS_DEBUG "-g" CACHE INTERNAL "asm compiler flags debug")
 SET(CMAKE_EXE_LINKER_FLAGS_DEBUG "" CACHE INTERNAL "linker flags debug")
 
 SET(CMAKE_C_FLAGS_RELEASE "-Os -flto" CACHE INTERNAL "c compiler flags release")
@@ -68,7 +68,6 @@ FUNCTION(STM32_ADD_HEX_BIN_TARGETS TARGET)
     ENDIF()
     ADD_CUSTOM_TARGET(${TARGET}.hex DEPENDS ${TARGET} COMMAND ${CMAKE_OBJCOPY} -Oihex ${FILENAME} ${FILENAME}.hex)
     ADD_CUSTOM_TARGET(${TARGET}.bin DEPENDS ${TARGET} COMMAND ${CMAKE_OBJCOPY} -Obinary ${FILENAME} ${FILENAME}.bin)
-    ADD_CUSTOM_TARGET(${TARGET}.elf DEPENDS ${TARGET} COMMAND ${CMAKE_OBJCOPY} -Oelf32-little ${FILENAME} ${FILENAME}.elf)
 ENDFUNCTION()
 
 STRING(TOLOWER ${STM32_FAMILY} STM32_FAMILY_LOWER)