arm64: dts: qcom: sc8280xp: correct ref_aux clock for ufs_mem_phy

The first UFS host controller fails to start on the SA8540P automotive
board (QDrive3) due to the following errors:

    ufshcd-qcom 1d84000.ufs: ufshcd_query_flag: Sending flag query for idn 18 failed, err = 253
    ufshcd-qcom 1d84000.ufs: ufshcd_query_flag: Sending flag query for idn 18 failed, err = 253
    ufshcd-qcom 1d84000.ufs: ufshcd_query_flag: Sending flag query for idn 18 failed, err = 253
    ufshcd-qcom 1d84000.ufs: ufshcd_query_flag_retry: query attribute, opcode 5, idn 18, failed
        with error 253 after 3 retries

The system eventually fails to boot with the warning:

    gcc_ufs_phy_axi_clk status stuck at 'off'

This issue can be worked around by adding clk_ignore_unused to the
kernel command line since the system firmware sets up this clock for us.

Let's fix this issue by updating the ref_aux clock on ufs_mem_phy. Note
that the downstream MSM 5.4 sources list this as ref_clk_parent. With
this patch, the SA8540P is able to be booted without clk_ignore_unused.

Signed-off-by: Brian Masney <bmasney@redhat.com>
Fixes: 152d1faf ("arm64: dts: qcom: add SC8280XP platform")