Update arm_convolve_HWC_q15_fast.c

CMSIS/NN/Source/ConvolutionFunctions/arm_convolve_HWC_q15_fast.c

@@ -72,7 +72,7 @@
  *
  * ch_im_in is multiple of 2
  *
- * ch_im_out is multipe of 2
+ * ch_im_out is multiple of 2
  *
  */