sata: ahci-da850: implement a workaround for the softreset quirk

[ Upstream commit f4d435f3265661d04e5290a0a0450e3a38898128 ]

There's an issue with the da850 SATA controller: if port multiplier
support is compiled in, but we're connecting the drive directly to
the SATA port on the board, the drive can't be detected.

To make SATA work on the da850-lcdk board: first try to softreset
with pmp - if the operation fails with -EBUSY, retry without pmp.

Signed-off-by: Bartosz Golaszewski <bgolaszewski@baylibre.com>
Acked-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Sekhar Nori <nsekhar@ti.com>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>