[arch][arm] Add support for float/nofloat compile options

Was already added to arm64, but arch/arm hadn't picked up this feature
yet. Uncovered a few places here or there that wasn't marking code as
float/no-float, but this fixes a problem where newer compilers are
starting to sneak in vector code because they can.

Issue #406

arch/arm/arm-m/arch.c

@@ -101,11 +101,6 @@ void arch_init(void) {
     CoreDebug->DEMCR |= CoreDebug_DEMCR_TRCENA_Msk;
     DWT->CYCCNT = 0;
     DWT->CTRL |= DWT_CTRL_CYCCNTENA_Msk; // enable cycle counter
-#endif
-    printf("CONTROL 0x%x\n", __get_CONTROL());
-#if (__FPU_PRESENT == 1) && (__FPU_USED == 1)
-    printf("FPSCR 0x%x\n", __get_FPSCR());
-    printf("FPCCR 0x%x\n", FPU->FPCCR);
 #endif
 }