EDAC, skx: Fix randconfig builds

EDAC, skx: Fix randconfig builds

The driver depends on the ADXL component glue and selects it. However,
ADXL itself implicitly depends on ACPI and in nonsensical randconfig
builds like this:

  # CONFIG_ACPI is not set
  CONFIG_ACPI_ADXL=y

where ACPI is not enabled, the build fails with:

  drivers/edac/skx_edac.o: In function `skx_mce_check_error':
  skx_edac.c:(.text+0xab): undefined reference to `adxl_decode'
  drivers/edac/skx_edac.o: In function `skx_init':
  skx_edac.c:(.init.text+0x8bf): undefined reference to `adxl_get_component_names'
  make: *** [vmlinux] Error 1

Add stubs for that case so that the build succeeds. CONFIG_ACPI=n
doesn't make any sense for real configurations but this fix will at
least silence randconfig builds.

Signed-off-by: Borislav Petkov <bp@suse.de>
Acked-by: Tony Luck <tony.luck@intel.com>
Cc: "Rafael J. Wysocki" <rafael@kernel.org>