phy: meson-axg-mipi: Rename "priv_auto_alloc_size" to "priv_auto"

With commit 41575d8e ("dm: treewide: Rename auto_alloc_size members
to be shorter") "priv_auto_alloc_size" was renamed to "priv_auto". Apply
the rename to these two drivers as well.

Fixes: 4547551a ("phy: Add Amlogic AXG MIPI PCIe Analog PHY driver")
Fixes: 7ef19503 ("phy: Add Amlogic AXG MIPI D-PHY driver")
Signed-off-by: Alper Nebi Yasak <alpernebiyasak@gmail.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Neil Armstrong <narmstrong@baylibre.com>