bpf, arm: fix emit_ldx_r and emit_mov_i using TMP_REG_1

emit_ldx_r() and emit_a32_mov_i() were both using TMP_REG_1 and
clashing with each other. Using TMP_REG_2 in emit_ldx_r() fixes
the issue.

Fixes: ec19e02b343 ("ARM: net: bpf: fix LDX instructions")
Cc: Russell King <rmk+kernel@armlinux.org.uk>
Signed-off-by: Nicolas Schichan <nschichan@freebox.fr>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>