bpf: use w regs in 32-bit non-fetch atomic pseudo-c

The 32-bit non-fetching atomic instructions treat the source register as
32-bits, which means in the pseudo-c syntax the "w" registers should be
used rather than the "r" registers.

opcodes/

	* bpf-opc-c (bpf_opcodes): Use %sw for AAD32, AOR32, AAND32
	and AXOR32 pseudo-c dialect asm templates.

gas/

	* testsuite/gas/bpf/atomic-be-pseudoc.d: Use "w" for source reg
	in non-fetching 32-bit atomic instructions.
	* testsuite/gas/bpf/atomic-pseudoc.d: Likewise.
	* testsuite/gas/bpf/atomic-pseudoc.s: Likewise.