Revert "usb: typec: bus: verify partner exists in typec_altmode_attention"

This reverts commit 0d3b5fe4 which is
commit f2364330 upstream.

It breaks the Android ABI and is not needed for Android systems at this
point in time.  If needed in the future, it can come back in an abi-safe
way.

Bug: 161946584
Change-Id: Ib271c569a1f86228f86e4c9b164d96f1bf0f0019
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>