generic: Convert incorrect generic/5.10 patches

OpenWRT's developer guide prefers having actual patches so they an be
sent upstream more easily.

However, in this case, Adding proper fields also allows for `git am` to
properly function. Some of these patches are quite old, and lack much
traceable history.

This commit tries to rectify that, by digging in the history to find
where and how it was first added.

It is by no means perfect and also shows some patches that should have
been long gone.

Signed-off-by: Olliver Schinagl <oliver@schinagl.nl>

target/linux/generic/pending-5.15/487-mtd-spinand-Add-support-for-Etron-EM73D044VCx.patch

@@ -1,3 +1,43 @@
+From f32085fc0b87049491b07e198d924d738a1a2834 Mon Sep 17 00:00:00 2001
+From: Daniel Danzberger <daniel@dd-wrt.com>
+Date: Wed, 3 Aug 2022 17:31:03 +0200
+Subject: [PATCH] mtd: spinand: Add support for Etron EM73D044VCx
+
+Airoha is a new ARM platform based on Cortex-A53 which has recently been
+merged into linux-next.
+
+Due to BootROM limitations on this platform, the Cortex-A53 can't run in
+Aarch64 mode and code must be compiled for 32-Bit ARM.
+
+This support is based mostly on those linux-next commits backported
+for kernel 5.15.
+
+Patches:
+1 - platform support = linux-next
+2 - clock driver = linux-next
+3 - gpio driver = linux-next
+4 - linux,usable-memory-range dts support = linux-next
+5 - mtd spinand driver
+6 - spi driver
+7 - pci driver (kconfig only, uses mediatek PCI) = linux-next
+
+Still missing:
+- Ethernet driver
+- Sysupgrade support
+
+A.t.m there exists one subtarget EN7523 with only one evaluation
+board.
+
+The initramfs can be run with the following commands from u-boot:
+-
+u-boot> setenv bootfile \
+	openwrt-airoha-airoha_en7523-evb-initramfs-kernel.bin
+u-boot> tftpboot
+u-boot> bootm 0x81800000
+-
+
+Submitted-by: Daniel Danzberger <daniel@dd-wrt.com>
+
 --- a/drivers/mtd/nand/spi/Makefile
 +++ b/drivers/mtd/nand/spi/Makefile
 @@ -1,3 +1,3 @@