cpu,opcodes,gas: fix neg and neg32 instructions in BPF

cpu,opcodes,gas: fix neg and neg32 instructions in BPF

This patch fixes the neg/neg32 BPF instructions, which have K (=0)
instead of X (=1) in their header source bit, despite operating on
registes.

cpu/ChangeLog:

2020-01-30  Jose E. Marchesi  <jose.marchesi@oracle.com>

	* bpf.cpu (define-alu-insn-un): The unary BPF instructions
	(neg and neg32) use OP_SRC_K even if they operate only in
	registers.

opcodes/ChangeLog:

2020-01-30  Jose E. Marchesi  <jose.marchesi@oracle.com>

	* bpf-opc.c: Regenerate.

gas/ChangeLog:

2020-01-30  Jose E. Marchesi  <jose.marchesi@oracle.com>

	* testsuite/gas/bpf/alu.d: Update expected opcode for `neg'.
	* testsuite/gas/bpf/alu-be.d: Likewise.
	* testsuite/gas/bpf/alu32.d: Likewise for `neg32'.
	* testsuite/gas/bpf/alu32-be.d: Likewise.