ARM: at91: Remove unused extern declarations

commit 157576d5 ("misc: remove atmel_tclib")
left behind this.
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Link: https://lore.kernel.org/r/20230725141105.26904-1-yuehaibing@huawei.comSigned-off-by: Claudiu Beznea <claudiu.beznea@tuxon.dev>

include/soc/at91/atmel_tcb.h

@@ -77,9 +77,6 @@ struct atmel_tc {
 	bool			allocated;
 };
 
-extern struct atmel_tc *atmel_tc_alloc(unsigned block);
-extern void atmel_tc_free(struct atmel_tc *tc);
-
 /* platform-specific ATMEL_TC_TIMER_CLOCKx divisors (0 means 32KiHz) */
 extern const u8 atmel_tc_divisors[5];