firmware: dmi_scan: Rename dmi_table to dmi_decode_table

The "dmi_table" function looks like data instance, but it does DMI
table decode. This patch renames it to "dmi_decode_table" name as
more appropriate. That allows us to use "dmi_table" name for correct
purposes.

Signed-off-by: Ivan Khoronzhuk <ivan.khoronzhuk@globallogic.com>
Signed-off-by: Jean Delvare <jdelvare@suse.de>