Currently mount matrix is allowed in Device Tree, though there is
no technical issue to extend it to support ACPI.

Convert the function to use device_property_read_string_array() and
thus allow to read mount matrix from ACPI if available.

Example of use in _DSD method:

  Name (_DSD, Package ()
  {
     ToUUID("daffd814-6eba-4d8c-8a91-bc9bbf4aa301"),
     Package ()
     {
        Package () { "mount-matrix", Package() {
                "1", "0",     "0",
                "0", "0.866", "0.5",
                "0", "-0.5",  "0.866",
        } },
     }
  })

At the same time drop the "of" prefix from its name and
convert current users.

No functional change intended.
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>