SMBIOS: Rename symbols to better reflect future use

Rename the following symbols:

  - smbios_set_type1_defaults() to the more general smbios_set_defaults();
  - bool smbios_type1_defaults to the more general smbios_defaults;
  - smbios_get_table() to smbios_get_table_legacy();

This patch contains no functional changes.

Signed-off-by: Gabriel Somlo <somlo@cmu.edu>
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>