staging: fsl-mc/dpio: allow the driver to compile multi-arch

Drop dependency on ARCH_LAYERSCAPE (which in turn depends on ARM64),
thus allowing this driver to compile on all architectures supported
by the fsl-mc bus driver.

This was compile tested on:
 - powerpc (corenet_basic_defconfig, ppc64_defconfig)
 - x86 (i386_defconfig, x86_64_defconfig, needs CONFIG_OF)
 - arm64 (defconfig)
Signed-off-by: NIoana Radulescu <ruxandra.radulescu@nxp.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/fsl-mc/bus/Kconfig

@@ -7,7 +7,7 @@
 
 config FSL_MC_DPIO
         tristate "QorIQ DPAA2 DPIO driver"
-        depends on FSL_MC_BUS && ARCH_LAYERSCAPE
+        depends on FSL_MC_BUS
         help
 	  Driver for the DPAA2 DPIO object.  A DPIO provides queue and
 	  buffer management facilities for software to interact with