Avoid using standard includes namely stdint.h, string.h, stdlib.h, etc. All standard include except stddef.h give compilation error due to differences in RISC-V toolchain configuration. Typically, the compilation error is related to "gnu-stubs-lp64.h". This patch fixes compile error caused by standard includes by providing substitutes of definetions provided by standard includes wherever required. Signed-off-by: Anup Patel <anup.patel@wdc.com>