reset: uniphier: fix USB clock line for LD20

reset: uniphier: fix USB clock line for LD20

BugLink: http://bugs.launchpad.net/bugs/1794889
[ Upstream commit e6914365fd280fce303a89b8a8d4529af5a2e0f9 ]

For LD20, the bit 5 of the offset 0x200c turned out to be a USB3
reset.  The hardware document says it is the GIO reset despite LD20
has no GIO bus, confusingly.

Also, fix confusing comments for PXs3.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
Signed-off-by: Stefan Bader <stefan.bader@canonical.com>