libc/stdio: remove unnecessary lib_libdtoa.c file (#4300)
libc/stdio: remove unnecessary lib_libdtoa.c file (#4300)

Legacy lib_dtoa was deleted by commit a499b8e. This lib_libdtoa.c
was a part of regacy so that it should be deleted together.

Signed-off-by: sunghan-chang <c954e25285721d8faa8b1a5c1ae2ef5a35338d32@samsung.com>
pillip8282/TizenRT,jeongchanKim/TizenRT,an4967/TizenRT,jsdosa/TizenRT,jeongchanKim/TizenRT,junmin-kim/TizenRT,Samsung/TizenRT,pillip8282/TizenRT,jeongchanKim/TizenRT,Samsung/TizenRT,jeongchanKim/TizenRT,jeongarmy/TizenRT,sunghan-chang/TizenRT,junmin-kim/TizenRT,sunghan-chang/TizenRT,junmin-kim/TizenRT,sunghan-chang/TizenRT,junmin-kim/TizenRT,sunghan-chang/TizenRT,an4967/TizenRT,jeongchanKim/TizenRT,Samsung/TizenRT,junmin-kim/TizenRT,pillip8282/TizenRT,Samsung/TizenRT,jsdosa/TizenRT,jeongarmy/TizenRT,jeongarmy/TizenRT,sunghan-chang/TizenRT,jeongarmy/TizenRT,junmin-kim/TizenRT,an4967/TizenRT,Samsung/TizenRT,jsdosa/TizenRT,Samsung/TizenRT,an4967/TizenRT,sunghan-chang/TizenRT,pillip8282/TizenRT,an4967/TizenRT,jeongchanKim/TizenRT,Samsung/TizenRT,jsdosa/TizenRT,sunghan-chang/TizenRT,pillip8282/TizenRT,pillip8282/TizenRT,pillip8282/TizenRT,an4967/TizenRT,jsdosa/TizenRT,jsdosa/TizenRT,jeongarmy/TizenRT,jeongchanKim/TizenRT,jeongarmy/TizenRT,junmin-kim/TizenRT,an4967/TizenRT,jsdosa/TizenRT,jeongarmy/TizenRT