sony_acpi: Allow multiple sony_acpi_values for the same .name

The acpi handles are kept _only_ if both the requested .acpiget and .acpiset
are available in the DSDT.
Currently only the SCDP/CDPW dualism is known.

Signed-off-by: Mattia Dongili <malattia@linux.it>
Signed-off-by: Len Brown <len.brown@intel.com>