Update from unstable

v.2020.04 from upstream.

• ported patches from Apertis
• supported boot on Sabrelite only

This is the first MR from series.

debian/patches/apertis/pstore/0001-Add-pstore-command.patch

@@ -114,12 +114,12 @@ diff --git a/cmd/Makefile b/cmd/Makefile
 index f1dd513a4b..06d7ad7375 100644
 --- a/cmd/Makefile
 +++ b/cmd/Makefile
-@@ -106,6 +106,7 @@ obj-$(CONFIG_CMD_PCI) += pci.o
+@@ -110,6 +110,7 @@ obj-$(CONFIG_CMD_PCI) += pci.o
  endif
- obj-y += pcmcia.o
  obj-$(CONFIG_CMD_PINMUX) += pinmux.o
+ obj-$(CONFIG_CMD_PMC) += pmc.o
 +obj-$(CONFIG_CMD_PSTORE) += pstore.o
- obj-$(CONFIG_CMD_PXE) += pxe.o
+ obj-$(CONFIG_CMD_PXE) += pxe.o pxe_utils.o
  obj-$(CONFIG_CMD_WOL) += wol.o
  obj-$(CONFIG_CMD_QFW) += qfw.o
 diff --git a/cmd/pstore.c b/cmd/pstore.c