misc: delete Makefile.rej

I accidentally added drivers/misc/Makefile.rej when applying the
mrvl-cn10k-dpi by hand.  Remove it as it's not needed.

Reported-by: Stephen Rothwell <sfr@canb.auug.org.au>
Fixes: 5f67eef6 ("misc: mrvl-cn10k-dpi: add Octeon CN10K DPI administrative driver")
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>