phy: qcom: phy-qcom-m31: change m31_ipq5332_regs to static

m31_ipq5332_regs is only used in phy-qcom-m31.c now, change
it to static.

Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
Reviewed-by: Varadarajan Narayanan <quic_varada@quicinc.com>
Link: https://lore.kernel.org/r/20230824092356.1154839-1-yangyingliang@huawei.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>