and remove CONFIG_LIBC_LONG_LONG option to simplify the usage.
note: the size will increase 668
before change:
text data bss dec hex filename
168440 348 4480 173268 2a4d4 nuttx
after change:
text data bss dec hex filename
169108 348 4480 173936 2a770 nuttx
Signed-off-by: Xiang Xiao <xiaoxiang@xiaomi.com>