arm64: errata: Provide macro for major and minor cpu revisions

Definition of cpu ranges are hard to read if the cpu variant is not
zero. Provide MIDR_CPU_VAR_REV() macro to describe the full hardware
revision of a cpu including variant and (minor) revision.

Change-Id: Iefda79a51242da145e2eeb734d0435cdccb3bac9
Signed-off-by: Robert Richter <rrichter@cavium.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Git-commit: fa5ce3d1928c441c3d241c34a00c07c8f5880b1a
Git-repo: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git


Signed-off-by: Kyle Yan <kyan@codeaurora.org>