Rev 1.5 microsoms include eMMC support on-board.  Add a microsom include
file which can be used to add support for this.
Signed-off-by: NRussell King <rmk+kernel@armlinux.org.uk>
Reviewed-by: NFabio Estevam <fabio.estevam@nxp.com>
Signed-off-by: NShawn Guo <shawnguo@kernel.org>