RISC-V: Add macro for ilp32e ABI. Cleanup white space.

RISC-V: Add macro for ilp32e ABI.  Cleanup white space.

	gcc/
	* config/riscv/riscv-c.c (riscv_cpu_cpp_builtins): For ABI_ILP32E,
	also define __riscv_abi_rve.  Delete trailing white space.

From-SVN: r264821