msm: pil: Delay after deasserting subsystem restart bits on 8974

The effects clearing *_RESTART registers are not immediate. A delay
is needed to ensure the subsystem is ready-to-go before registers
within it are manipulated. Fix this.

Change-Id: I12a996a7b5bf34c54a220aae90e8446f94dbdf8c
Signed-off-by: Matt Wagantall <mattw@codeaurora.org>
diff --git a/arch/arm/mach-msm/pil-q6v5-mss.c b/arch/arm/mach-msm/pil-q6v5-mss.c
index 62685ca..ff0e792d 100644
--- a/arch/arm/mach-msm/pil-q6v5-mss.c
+++ b/arch/arm/mach-msm/pil-q6v5-mss.c
@@ -139,8 +139,10 @@
 	struct q6v5_data *drv = dev_get_drvdata(pil->dev);
 	int ret;
 
+	/* Deassert reset to subsystem and wait for propagation */
 	writel_relaxed(0, drv->restart_reg);
 	mb();
+	udelay(2);
 
 	/*
 	 * Bring subsystem out of reset and enable required