generic: Create generic board infrastructure and move misc.h to it

Instead of creating a misc.h file in each board directory, create a
generic board directory and declare misc.h there.

Signed-off-by: Kevin O'Connor <kevin@koconnor.net>

src/simulator/Makefile

@@ -1,3 +1,4 @@
 # Additional simulator build rules
 
 src-y += simulator/main.c simulator/gpio.c
+src-y += generic/crc16_ccitt.c generic/alloc.c

src/simulator/misc.h

@@ -1,21 +0,0 @@
-#ifndef __SIMU_MISC_H
-#define __SIMU_MISC_H
-
-#include <stdint.h>
-
-// main.c
-char *console_get_input(uint8_t *plen);
-void console_pop_input(uint8_t len);
-char *console_get_output(uint8_t len);
-void console_push_output(uint8_t len);
-
-static inline size_t alloc_maxsize(size_t reqsize) {
-    return reqsize;
-}
-
-#define HAVE_OPTIMIZED_CRC 0
-static inline uint16_t _crc16_ccitt(char *buf, uint8_t len) {
-    return 0;
-}
-
-#endif // misc.h