staging: kpc2000: kpc_dma: rename show function per convention

Rename show_engine_regs show function to engine_regs_show as per the
convention followed. The show function macro DEVICE_ATTR also replaced
by DEVICE_ATTR_RO. Issue reported by checkpatch script.

Signed-off-by: Deepak R Varma <mh12gx2825@gmail.com>
Link: https://lore.kernel.org/r/9c8c0d60cec70b99f55d6e228b7585d47be695c2.1603734679.git.mh12gx2825@gmail.com


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>