RCC_BDCR
KER_CLK(RCC_BDCR, 15, RCC_BDCR, 8, 2, "rtc_ck", rtc_src);
RCC_BDCR + base,
GATE(CK_LSE, "ck_lse", "clk-lse", 0, RCC_BDCR, 0, 0),
_GATE(RCC_BDCR, 20, 0),
_MUX(RCC_BDCR, 16, 2, 0),