[vim] remove vim expandtab comments on most of the files

dev/timer/arm_cortex_a9/arm_cortex_a9_timer.c

@@ -223,5 +223,3 @@ static void arm_cortex_a9_timer_init_percpu(uint level)
 LK_INIT_HOOK_FLAGS(arm_cortex_a9_timer_init_percpu,
                    arm_cortex_a9_timer_init_percpu,
                    LK_INIT_LEVEL_THREADING - 1, LK_INIT_FLAG_SECONDARY_CPUS);
-
-/* vim: set ts=4 sw=4 expandtab: */

dev/timer/arm_generic/arm_generic_timer.c

@@ -374,5 +374,3 @@ static void arm_generic_timer_resume_cpu(uint level)
 
 LK_INIT_HOOK_FLAGS(arm_generic_timer_resume_cpu, arm_generic_timer_resume_cpu,
                    LK_INIT_LEVEL_PLATFORM, LK_INIT_FLAG_CPU_RESUME);
-
-/* vim: set noexpandtab: */