Doc: driver-api: ipmi: Add description of alerts_broken module param

Add description about alerts_broken module parameter of ipmi_ssif driver
which skips enabling SMBus alert during setup.
Signed-off-by: Misono Tomohiro <misono.tomohiro@jp.fujitsu.com>
Message-Id: <20200624065405.17653-3-misono.tomohiro@jp.fujitsu.com>
Signed-off-by: Corey Minyard <cminyard@mvista.com>

Documentation/driver-api/ipmi.rst

@@ -516,6 +516,7 @@ at module load time (for a module) with::
 	slave_addrs=<addr1>,<addr2>,...
 	tryacpi=[0|1] trydmi=[0|1]
 	[dbg_probe=1]
+	alerts_broken
 
 The addresses are normal I2C addresses.  The adapter is the string
 name of the adapter, as shown in /sys/class/i2c-adapter/i2c-<n>/name.
@@ -537,6 +538,9 @@ The slave_addrs specifies the IPMI address of the local BMC.  This is
 usually 0x20 and the driver defaults to that, but in case it's not, it
 can be specified when the driver starts up.
 
+alerts_broken does not enable SMBus alert for SSIF. Otherwise SMBus
+alert will be enabled on supported hardware.
+
 Discovering the IPMI compliant BMC on the SMBus can cause devices on
 the I2C bus to fail. The SMBus driver writes a "Get Device ID" IPMI
 message as a block write to the I2C bus and waits for a response.