arm: config: fix default console only to specify the device

arm: config: fix default console only to specify the device

This reverts commit 767edf0f6b3eaa0303f3fd6afdc14ddce0aca70c and restores
commit 232ed3ca534708527a9515c7c41bc3542949525c.

Debian's flash-kernel expect the console variable to just contain the device,
because it will set the bootargs to "console=${console}". So revert adding
"console=" to the console parameter, but also adjust the shipped bootscripts
for exynos boards to cope with it.

Bug-Debian: https://bugs.debian.org/920116
Signed-off-by: Benjamin Drung <bdrung@debian.org>
Gbp-Pq: Topic exynos
Gbp-Pq: Name 0001-arm-config-fix-default-console-only-to-specify-the-d.patch