docs: ipmb: place it at driver-api and convert to ReST

No new doc should be added at the main Documentation/ directory.

Instead, new docs should be added as ReST files, within the
Kernel documentation body.

Fixes: 51bd6f2915 ("Add support for IPMB driver")
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>
Message-Id: <d23c36ca65fe6ad56af1723bf70f7a7f4154c410.1561804596.git.mchehab+samsung@kernel.org>
Signed-off-by: Corey Minyard <cminyard@mvista.com>

Documentation/driver-api/index.rst

@@ -34,6 +34,7 @@ available subsections can be seen below.
    pci/index
    spi
    i2c
+   ipmb
    i3c/index
    hsi
    edac

Documentation/driver-api/ipmb.rst

@@ -48,7 +48,7 @@ CONFIG_IPMB_DEVICE_INTERFACE=y
 
 1) If you want the driver to be loaded at boot time:
 
-a) Add this entry to your ACPI table, under the appropriate SMBus:
+a) Add this entry to your ACPI table, under the appropriate SMBus::
 
      Device (SMB0) // Example SMBus host controller
      {
@@ -63,7 +63,7 @@ Device (SMB0) // Example SMBus host controller
        }
      }
 
-b) Example for device tree:
+b) Example for device tree::
 
      &i2c2 {
             status = "okay";
@@ -74,7 +74,8 @@ b) Example for device tree:
             };
      };
 
-2) Manually from Linux:
+2) Manually from Linux::
+
      modprobe ipmb-dev-int
 
 
@@ -86,15 +87,16 @@ described in 'Documentation/i2c/instantiating-devices'.
 If you have multiple BMCs, each connected to your Satellite MC via
 a different I2C bus, you can instantiate a device for each of
 those BMCs.
+
 The name of the instantiated device contains the I2C bus number
-associated with it as follows:
+associated with it as follows::
 
   BMC1 ------ IPMB/I2C bus 1 ---------|   /dev/ipmb-1
 				Satellite MC
   BMC1 ------ IPMB/I2C bus 2 ---------|   /dev/ipmb-2
 
 For instance, you can instantiate the ipmb-dev-int device from
-user space at the 7 bit address 0x10 on bus 2:
+user space at the 7 bit address 0x10 on bus 2::
 
   # echo ipmb-dev 0x1010 > /sys/bus/i2c/devices/i2c-2/new_device