esp8266/etshal: delete incorrect function prototypes

these are function prototypes not used in circuitpython.  The
declarations began to conflict with ones in the upstream SDK
at some point, so delete them.

Author: jepler

esp8266/etshal.h

@@ -6,14 +6,12 @@
 // see http://esp8266-re.foogod.com/wiki/Random_Number_Generator
 #define WDEV_HWRNG ((volatile uint32_t*)0x3ff20e44)
 
-void ets_delay_us();
 void ets_intr_lock(void);
 void ets_intr_unlock(void);
 void ets_isr_mask(uint32_t mask);
 void ets_isr_unmask(uint32_t mask);
 void ets_isr_attach(int irq_no, void (*handler)(void *), void *arg);
 void ets_install_putc1();
-void uart_div_modify();
 void ets_set_idle_cb(void (*handler)(void *), void *arg);
 
 void ets_timer_arm_new(os_timer_t *tim, uint32_t millis, bool repeat, bool is_milli_timer);
@@ -32,12 +30,6 @@ void MD5Init(MD5_CTX *context);
 void MD5Update(MD5_CTX *context, const void *data, unsigned int len);
 void MD5Final(unsigned char digest[16], MD5_CTX *context);
 
-// These prototypes are for recent SDKs with "malloc tracking"
-void *pvPortMalloc(unsigned sz, const char *fname, int line);
-void *pvPortZalloc(unsigned sz, const char *fname, int line);
-void *pvPortRealloc(void *p, unsigned sz, const char *fname, int line);
-void vPortFree(void *p, const char *fname, int line);
-
 uint32_t SPIRead(uint32_t offset, void *buf, uint32_t len);
 uint32_t SPIWrite(uint32_t offset, const void *buf, uint32_t len);
 uint32_t SPIEraseSector(int sector);