samples: wifi: fix build warning of DIV_ROUND_UP redefined

Remove CONFIG_MBEDTLS_HAVE_TIME_DATE, which will cause that mbedtls
include Zephyr time.h and leads to 'DIV_ROUND_UP' redefined warning.

Signed-off-by: Maochen Wang <[email protected]>

Author: MaochenWang1

samples/net/wifi/boards/rd_rw612_bga.conf

@@ -93,7 +93,6 @@ CONFIG_MBEDTLS=y
 CONFIG_MBEDTLS_BUILTIN=y
 CONFIG_MBEDTLS_USER_CONFIG_ENABLE=y
 CONFIG_MBEDTLS_USER_CONFIG_FILE="wpa_supp_els_pkc_mbedtls_config.h"
-CONFIG_MBEDTLS_HAVE_TIME_DATE=y
 
 # Include els_pkc in build
 CONFIG_ENTROPY_GENERATOR=y