ANDROID: GKI: arm64: drop CONFIG_DEBUG_PREEMPT forced disable

In commit db4677b3 ("lib/Kconfig.debug: do not enable DEBUG_PREEMPT
by default"), DEBUG_PREEMPT is not enabled by default, so our explicit
turning it off is no longer needed.  This fixes the arm64 gki builds.

Fixes: db4677b3 ("lib/Kconfig.debug: do not enable DEBUG_PREEMPT by default")
Change-Id: I4491bceb3735d966731717f13b1e2395c9b7206a
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>