MIPS: e55_defconfig: Convert to use libata PATA drivers

IDE subsystem has been deprecated since 2009 and the majority
(if not all) of Linux distributions have switched to use
libata for ATA support exclusively.  However there are still
some users (mostly old or/and embedded non-x86 systems) that
have not converted from using IDE subsystem to libata PATA
drivers.  This doesn't seem to be good thing in the long-term
for Linux as while there is less and less PATA systems left
in use:

* testing efforts are divided between two subsystems

* having duplicate drivers for same hardware confuses users

This patch converts e55_defconfig to use libata PATA drivers.

PS This platform still uses "ide0=base[,ctl[,irq]]" hack in
its defconfig.  The hack itself has been removed in 2008 and
this platform should be converted to using PATA platform host
driver (pata_platform) instead.

Cc: Yoichi Yuasa <yoichi_yuasa@tripeaks.co.jp>
Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>