kernel: backport 4.18 patch adding DMI_PRODUCT_SKU

It's needed for applying some hardware quirks. This fixes:
drivers/net/wireless/broadcom/brcm80211/brcmfmac/dmi.c:60:20: error: 'DMI_PRODUCT_SKU' undeclared here (not in a function); did you mean 'DMI_PRODUCT_UUID'?
    DMI_EXACT_MATCH(DMI_PRODUCT_SKU, "T8"),

Fixes: 8888cb725d49 ("mac80211: brcm: backport remaining brcmfmac 5.2 patches")
Signed-off-by: Rafał Miłecki <[email protected]>

target/linux/generic/backport-4.14/900-v4.18-firmware-dmi-Add-access-to-the-SKU-ID-string.patch

@@ -0,0 +1,57 @@
+From b23908d3c48a37c46c6a26df2cdeab1610b360ba Mon Sep 17 00:00:00 2001
+From: Simon Glass <[email protected]>
+Date: Sun, 17 Jun 2018 14:09:42 +0200
+Subject: [PATCH] firmware: dmi: Add access to the SKU ID string
+
+This is used in some systems from user space for determining the identity
+of the device.
+
+Expose this as a file so that that user-space tools don't need to read
+from /sys/firmware/dmi/tables/DMI
+
+Signed-off-by: Simon Glass <[email protected]>
+Signed-off-by: Jean Delvare <[email protected]>
+---
+ drivers/firmware/dmi-id.c       | 2 ++
+ drivers/firmware/dmi_scan.c     | 1 +
+ include/linux/mod_devicetable.h | 1 +
+ 3 files changed, 4 insertions(+)
+
+--- a/drivers/firmware/dmi-id.c
++++ b/drivers/firmware/dmi-id.c
+@@ -47,6 +47,7 @@ DEFINE_DMI_ATTR_WITH_SHOW(product_name,
+ DEFINE_DMI_ATTR_WITH_SHOW(product_version,	0444, DMI_PRODUCT_VERSION);
+ DEFINE_DMI_ATTR_WITH_SHOW(product_serial,	0400, DMI_PRODUCT_SERIAL);
+ DEFINE_DMI_ATTR_WITH_SHOW(product_uuid,		0400, DMI_PRODUCT_UUID);
++DEFINE_DMI_ATTR_WITH_SHOW(product_sku,		0444, DMI_PRODUCT_SKU);
+ DEFINE_DMI_ATTR_WITH_SHOW(product_family,	0444, DMI_PRODUCT_FAMILY);
+ DEFINE_DMI_ATTR_WITH_SHOW(board_vendor,		0444, DMI_BOARD_VENDOR);
+ DEFINE_DMI_ATTR_WITH_SHOW(board_name,		0444, DMI_BOARD_NAME);
+@@ -193,6 +194,7 @@ static void __init dmi_id_init_attr_tabl
+ 	ADD_DMI_ATTR(product_serial,    DMI_PRODUCT_SERIAL);
+ 	ADD_DMI_ATTR(product_uuid,      DMI_PRODUCT_UUID);
+ 	ADD_DMI_ATTR(product_family,    DMI_PRODUCT_FAMILY);
++	ADD_DMI_ATTR(product_sku,       DMI_PRODUCT_SKU);
+ 	ADD_DMI_ATTR(board_vendor,      DMI_BOARD_VENDOR);
+ 	ADD_DMI_ATTR(board_name,        DMI_BOARD_NAME);
+ 	ADD_DMI_ATTR(board_version,     DMI_BOARD_VERSION);
+--- a/drivers/firmware/dmi_scan.c
++++ b/drivers/firmware/dmi_scan.c
+@@ -435,6 +435,7 @@ static void __init dmi_decode(const stru
+ 		dmi_save_ident(dm, DMI_PRODUCT_VERSION, 6);
+ 		dmi_save_ident(dm, DMI_PRODUCT_SERIAL, 7);
+ 		dmi_save_uuid(dm, DMI_PRODUCT_UUID, 8);
++		dmi_save_ident(dm, DMI_PRODUCT_SKU, 25);
+ 		dmi_save_ident(dm, DMI_PRODUCT_FAMILY, 26);
+ 		break;
+ 	case 2:		/* Base Board Information */
+--- a/include/linux/mod_devicetable.h
++++ b/include/linux/mod_devicetable.h
+@@ -471,6 +471,7 @@ enum dmi_field {
+ 	DMI_PRODUCT_VERSION,
+ 	DMI_PRODUCT_SERIAL,
+ 	DMI_PRODUCT_UUID,
++	DMI_PRODUCT_SKU,
+ 	DMI_PRODUCT_FAMILY,
+ 	DMI_BOARD_VENDOR,
+ 	DMI_BOARD_NAME,