ARM: cti: fix manipulation of debug lock registers

The LOCKSTATUS register for memory-mapped coresight devices indicates
whether or not the device in question implements hardware locking. If
not, locking is not present (i.e. LSR.SLI == 0) and LAR is write-ignore,
so software doesn't actually need to check the status register at all.

This patch removes the broken LSR checks.

Cc: Ming Lei <ming.lei@canonical.com>
Reported-by: Mike Williams <michael.williams@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>

arch/arm/include/asm/cti.h

@@ -146,15 +146,7 @@ static inline void cti_irq_ack(struct cti *cti)
  */
 static inline void cti_unlock(struct cti *cti)
 {
-	void __iomem *base = cti->base;
+	__raw_writel(LOCKCODE, cti->base + LOCKACCESS);
-	unsigned long val;
-
-	val = __raw_readl(base + LOCKSTATUS);
-
-	if (val & 1) {
-		val = LOCKCODE;
-		__raw_writel(val, base + LOCKACCESS);
-	}
 }
 
 /**
@@ -166,14 +158,6 @@ static inline void cti_unlock(struct cti *cti)
  */
 static inline void cti_lock(struct cti *cti)
 {
-	void __iomem *base = cti->base;
+	__raw_writel(~LOCKCODE, cti->base + LOCKACCESS);
-	unsigned long val;
-
-	val = __raw_readl(base + LOCKSTATUS);
-
-	if (!(val & 1)) {
-		val = ~LOCKCODE;
-		__raw_writel(val, base + LOCKACCESS);
-	}
 }
 #endif