staging: fsl-mc: set cacheable flag for added devices if applicable

Some DPAA2 devices have mmio regions that should be mapped as
cacheable by drivers.  Set IORESOURCE_CACHEABLE in the region's
flags if applicable.

Signed-off-by: Itai Katz <itai.katz@nxp.com>
[Stuart: update subject and commit message]
Signed-off-by: Stuart Yoder <stuart.yoder@nxp.com>
Acked-by: German Rivera <german.rivera@nxp.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>