ACPI: Define struct acpi_device for CONFIG_ACPI unset

We may find use for struct acpi_device and acpi_bus_get_device() in
generic code without wanting to add #if IS_ENABLED(CONFIG_ACPI) churn
there.

Code can use ACPI_HANDLE() test to let compiler optimize out code
blocks that are not used in !CONFIG_ACPI builds but structure
definitions and function stubs must be available.

Define a stub struct acpi_device for CONFIG_ACPI unset containing dev
as the only member and a stub acpi_bus_get_device() always returning
an error code.

Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
i2c: Use stable dev_name for ACPI enumerated I2C slaves

Current I2C adapter id - client address "x-00yy" based device naming scheme
is not always stable enough to be used in name based matching, for instance
within ALSA SoC subsystem.

This is problematic in PC kind of platforms where I2C adapter numbers can
change due variable amount of bus controllers, probe order, add-on cards or
just because of BIOS settings.

This patch addresses the problem by using the ACPI device name with
"i2c-" prefix for ACPI enumerated I2C slaves. For them device name
"x-00yz" becomes "i2c-INTABCD:ij" after this patch.

Signed-off-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Acked-by: Wolfram Sang <wsa@the-dreams.de>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
spi: Use stable dev_name for ACPI enumerated SPI slaves

Current spi bus_num.chip_select "spix.y" based device naming scheme may not
be stable enough to be used in name based matching, for instance within
ALSA SoC subsystem.

This can be problem in PC kind of platforms if there are changes in SPI bus
configuration, amount of busses or probe order.

This patch addresses the problem by using the ACPI device name with
"spi-" prefix for ACPI enumerated SPI slave. For them device name
"spix.y" becomes "spi-INTABCD:ij".

Signed-off-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Acked-by: Mark Brown <broonie@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Merge branch 'acpi-assorted-next' into bleeding-edge

* acpi-assorted-next:
  spi: Use stable dev_name for ACPI enumerated SPI slaves
  i2c: Use stable dev_name for ACPI enumerated I2C slaves
  ACPI: Define struct acpi_device for CONFIG_ACPI unset