firmware/dmi: Include product_sku info to modalias

firmware/dmi: Include product_sku info to modalias

BugLink: https://bugs.launchpad.net/bugs/1938143
Some Dell platforms rely on modalias to customize configuration,
the product sku can be more specific for the hardware.

Add product_sku to modalias for better utilization.

Signed-off-by: Kai-Chuan Hsieh <kaichuan.hsieh@canonical.com>
Signed-off-by: Jean Delvare <jdelvare@suse.de>
(cherry picked from commit e26f023e01ef26b4138bc1099af309bdc4523d23)
Signed-off-by: Chia-Lin Kao (AceLan) <acelan.kao@canonical.com>
Acked-by: Tim Gardner <tim.gardner@canonical.com>
Acked-by: Stefan Bader <stefan.bader@canonical.com>
Signed-off-by: Kelsey Skunberg <kelsey.skunberg@canonical.com>