staging: dgnc: Add whitespace around OR'd flags ("|")

This patch fixes the checkpatch.pl message:

CHECK: spaces preferred around that '|' (ctx:VxV)
+	writeb((UART_FCR_ENABLE_FIFO|UART_FCR_CLEAR_RCVR|UART_FCR_CLEAR_XMIT),
                                    ^                   ^

As per the guidelines for coding style in the kernel, I have updated the
digi international driver to include spaces around the OR'd flags; not only
is this formatting issue caught by `checkpatch.pl`, in the next `if` block
the correct formatting is used, leading to both incorrect and inconsistent
code formatting.

This patch puts the line in question at 82 characters---while this is over
the recommended limit, there are no clear locations to break the line and it
barely breaks the cutoff.

Signed-off-by: Sam Horlbeck Olsen <sam.horlsen@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>