emlearn_iir_q15: Remove custom memset

Author: jonnor

src/emlearn_iir_q15/iir_filter.c

@@ -5,16 +5,6 @@
 
 #include <string.h>
 
-// memset is used by some standard C constructs
-#if !defined(__linux__)
-void *memcpy(void *dst, const void *src, size_t n) {
-    return mp_fun_table.memmove_(dst, src, n);
-}
-void *memset(void *s, int c, size_t n) {
-    return mp_fun_table.memset_(s, c, n);
-}
-#endif
-
 
 // MicroPython type for EmlIIR
 typedef struct _mp_obj_iir_filter_t {