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

platform/stellaris/init.c

@@ -90,5 +90,3 @@ void platform_init(void)
     printf("\n");
 
 }
-
-// vim: set ts=4 sw=4 noexpandtab:

platform/stellaris/usbc.c

@@ -250,5 +250,3 @@ status_t usbc_queue_tx(ep_t ep, usbc_transfer_t *transfer)
 {
     PANIC_UNIMPLEMENTED;
 }
-
-// vim: set ts=4 sw=4 noexpandtab:

platform/stellaris/vectab.c

@@ -297,5 +297,3 @@ const void *const __SECTION(".text.boot.vectab2") vectab2[] = {
     VECTAB_ENTRY(pwm1_gen3),                // PWM 1 Generator 3
     VECTAB_ENTRY(pwm1_fault)                // PWM 1 Fault
 };
-
-// vim: ts=4 sw=4 noexpandtab: