readl_poll_timeout() calls usleep_range() to sleep between reads.
usleep_range() doesn't work efficiently for tiny values.

Raise the polling delay in qcom_qmp_phy_enable() to bring it in line
with the delay in qcom_qmp_phy_com_init().

Signed-off-by: Marc Gonzalez <marc.w.gonzalez@free.fr>
Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>