lib: Kconfig.debug: Fix the recursive dependency

An earlier commit 52a3101e
added a recursive dependency as part of CONFIG_DEBUG_SPINLOCK

lib/Kconfig.debug:585:error: recursive dependency detected!
lib/Kconfig.debug:585:symbol DEBUG_SPINLOCK_BITE_ON_BUG depends on DEBUG_SPINLOCK_PANIC_ON_BUG
lib/Kconfig.debug:593:symbol DEBUG_SPINLOCK_PANIC_ON_BUG depends on DEBUG_SPINLOCK_BITE_ON_BUG

Fix this by adding a choice menu.

Change-Id: I0e50103397bb71dec7056db5148cba988550b860
Signed-off-by: Rohit Vaswani <rvaswani@codeaurora.org>