UPSTREAM: arm64: kernel: Add cpuid_feature_extract_field() for 4bit sign extension

Based on arch/arm/include/asm/cputype.h, this function does the
shifting and sign extension necessary when accessing cpu feature fields.

Signed-off-by: James Morse <james.morse@arm.com>
Suggested-by: Russell King <linux@arm.linux.org.uk>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>

Bug: 31432001
Change-Id: If754fc6e3ae821cf21d0cc79fb3932cf36635d67
(cherry picked from commit 79b0e09a3c9bd74ee54582efdb351179d7c00351)
Signed-off-by: Sami Tolvanen <samitolvanen@google.com>