kernel: add support for GD25D05 SPI NOR

This chip is used on newer RB912UAG-5HPnD r2 boards:

Before:

[    0.642553] m25p80 spi0.0: unrecognized JEDEC id bytes: c8, 40, 10
[    0.649381] NAND flash driver for the RouterBOARD 91x series

After:

[    0.641714] m25p80 spi0.0: found gd25d05, expected m25p80
[    0.649916] m25p80 spi0.0: gd25d05 (64 Kbytes)
[    0.655122] Creating 4 MTD partitions on "spi0.0":
[    0.660164] 0x000000000000-0x00000000c000 : "routerboot"
[    0.667782] 0x00000000c000-0x00000000d000 : "hard_config"
[    0.675073] 0x00000000d000-0x00000000e000 : "bios"
[    0.682613] 0x00000000e000-0x00000000f000 : "soft_config"
[    0.690304] NAND flash driver for the RouterBOARD 91x series

Signed-off-by: Koen Vandeputte <koen.vandeputte@ncentric.com>

target/linux/generic/pending-4.14/481-mtd-spi-nor-add-support-for-Gigadevice-GD25D05.patch

@@ -0,0 +1,29 @@
+From d68b4aa22e8c625685bfad642dd7337948dc0ad1 Mon Sep 17 00:00:00 2001
+From: Koen Vandeputte <koen.vandeputte@ncentric.com>
+Date: Mon, 6 Jan 2020 13:07:56 +0100
+Subject: [PATCH] mtd: spi-nor: add support for Gigadevice GD25D05
+
+Signed-off-by: Koen Vandeputte <koen.vandeputte@ncentric.com>
+---
+ drivers/mtd/spi-nor/spi-nor.c | 5 +++++
+ 1 file changed, 5 insertions(+)
+
+diff --git a/drivers/mtd/spi-nor/spi-nor.c b/drivers/mtd/spi-nor/spi-nor.c
+index f4afe123e9dc..a34fa42d47a2 100644
+--- a/drivers/mtd/spi-nor/spi-nor.c
++++ b/drivers/mtd/spi-nor/spi-nor.c
+@@ -2346,6 +2346,11 @@ static const struct flash_info spi_nor_ids[] = {
+ 	{ "mb85rs1mt", INFO(0x047f27, 0, 128 * 1024, 1, SPI_NOR_NO_ERASE) },
+ 
+ 	/* GigaDevice */
++	{
++		"gd25d05", INFO(0xc84010, 0, 64 * 1024,  1,
++			SECT_4K | SPI_NOR_DUAL_READ | SPI_NOR_QUAD_READ |
++			SPI_NOR_HAS_LOCK | SPI_NOR_HAS_TB)
++	},
+ 	{
+ 		"gd25q16", INFO(0xc84015, 0, 64 * 1024,  32,
+ 			SECT_4K | SPI_NOR_DUAL_READ | SPI_NOR_QUAD_READ |
+-- 
+2.17.1
+