ARM: 8564/1: fix cpu feature extracting helper

Commit b8c9592b "ARM: 8318/1: treat CPU feature register fields as signed
quantities" introduced helper to extract signed quantities of 4-bit
blocks. However, with a current code feature with value 0b1000 isn't
rejected as negative. So fix the "if" condition.
Reported-by: NJonathan Brawn <Jon.Brawn@arm.com>
Signed-off-by: NVladimir Murzin <vladimir.murzin@arm.com>
Acked-by: NArd Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: NRussell King <rmk+kernel@arm.linux.org.uk>

arch/arm/include/asm/cputype.h

@@ -276,7 +276,7 @@ static inline int __attribute_const__ cpuid_feature_extract_field(u32 features,
 	int feature = (features >> field) & 15;
 
 	/* feature registers are signed values */
-	if (feature > 8)
+	if (feature > 7)
 		feature -= 16;
 
 	return feature;