kernel: Make the patches apply on top of 4.19

This makes the patches which were just copied in the previous commit
apply on top of kernel 4.19.

The patches in the backports-4.19 folder were checked if they are really
in kernel 4.19 based on the title and only removed if they were found in
the upstream kernel.

The following additional patches form the pending folder went into
upstream Linux 4.19:
pending-4.19/171-usb-dwc2-Fix-inefficient-copy-of-unaligned-buffers.patch
pending-4.19/190-2-5-e1000e-Fix-wrong-comment-related-to-link-detection.patch
pending-4.19/478-mtd-spi-nor-Add-support-for-XM25QH64A-and-XM25QH128A.patch
pending-4.19/479-mtd-spi-nor-add-eon-en25qh32.patch
pending-4.19/950-tty-serial-exar-generalize-rs485-setup.patch
pending-4.19/340-MIPS-mm-remove-mips_dma_mapping_error.patch

Bigger changes were introduced to the m25p80 spi nor driver, as far as I
saw it in the new code, it now has the functionality provided in this
patch:
pending-4.19/450-mtd-m25p80-allow-fallback-from-spi_flash_read-to-reg.patch

Part of this patch went upstream independent of OpenWrt:
hack-4.19/220-gc_sections.patch
This patch was reworked to match the changes done upstream.

The MIPS DMA API changed a lot, this patch was rewritten to match the
new DMA handling:
pending-4.19/341-MIPS-mm-remove-no-op-dma_map_ops-where-possible.patch

I did bigger manual changes to the following patches and I am not 100% sure if they are all correct:
pending-4.19/0931-w1-gpio-fix-problem-with-platfom-data-in-w1-gpio.patch
pending-4.19/411-mtd-partial_eraseblock_write.patch
pending-4.19/600-netfilter_conntrack_flush.patch
pending-4.19/611-netfilter_match_bypass_default_table.patch
pending-4.19/670-ipv6-allow-rejecting-with-source-address-failed-policy.patch
hack-4.19/211-host_tools_portability.patch
hack-4.19/221-module_exports.patch
hack-4.19/321-powerpc_crtsavres_prereq.patch
hack-4.19/902-debloat_proc.patch

This is based on patchset from Marko Ratkaj <marko.ratkaj@sartura.hr>

Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>

target/linux/generic/pending-4.19/300-mips_expose_boot_raw.patch

@@ -9,7 +9,7 @@ Acked-by: Rob Landley <rob@landley.net>
 ---
 --- a/arch/mips/Kconfig
 +++ b/arch/mips/Kconfig
-@@ -1067,9 +1067,6 @@ config FW_ARC
+@@ -1059,9 +1059,6 @@ config FW_ARC
  config ARCH_MAY_HAVE_PC_FDC
  	bool
  
@@ -19,7 +19,7 @@ Acked-by: Rob Landley <rob@landley.net>
  config CEVT_BCM1480
  	bool
  
-@@ -2967,6 +2964,18 @@ choice
+@@ -2965,6 +2962,18 @@ choice
  		bool "Extend builtin kernel arguments with bootloader arguments"
  endchoice