serial: driver for m32 arch should not have DEC alpha errata

This driver was copied from the original 8250 driver and hence
got the DEC alpha errata workaround.  But the workaround is ugly
and we don't really want it in any more places than it absolutely
needs to be.  Obviously ARCH=m32r means ARCH != alpha, so just
remove the references to the ALPHA_KLUDGE_MCR define.

Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>