mt2503客制化的命令不识别

[DESCRIPTION]
客制化的AT命令不识别（如：AT*TSIMINS命令）根本没进入到客制化的处理函数。

[SOLUTION]
由于Customize ATcommand 目前支持“+”, “^”, “%”, “$”。
所以可以通过下面两种方法来解决：
1. 将 AT*TSIMINS 中“*” 改成 “+”, “^”, “%”, “$”
2. 如果有L4的代码也可以在rMMI_find_cmd_class()中增加一项支持“*”号。
if ((source_string_ptr->string_ptr[source_string_ptr->index] ==
RMMI_CHAR_PLUS ||
source_string_ptr->string_ptr[source_string_ptr->index] == RMMI_HAT ||
source_string_ptr->string_ptr[source_string_ptr->index] ==
RMMI_CHAR_PERCENT ||
source_string_ptr->string_ptr[source_string_ptr->index] == RMMI_MONEY) &&
(source_string_ptr->index <= MAX_MULTIPLE_CMD_INFO_LEN))
{
/* the '+' character is found,hence it is extended command */
ret_val = RMMI_EXTENDED_CMD;
rmmi_compute_symbol_hash(source_string_ptr);
source_string_ptr->index++; /* to get the next character */
}