refactor(pmu): move S31 dbias vol gap getter from efuse_ll to pmu_ll

Keep PMU calibration efuse reads in the PMU LL layer, matching other chips.

components/esp_hal_pmu/esp32s31/include/hal/pmu_ll.h

@@ -16,11 +16,17 @@
 #include "soc/pmu_struct.h"
 #include "hal/pmu_types.h"
 #include "hal/misc.h"
+#include "soc/efuse_struct.h"
 
 #ifdef __cplusplus
 extern "C" {
 #endif
 
+FORCE_INLINE_ATTR int32_t pmu_ll_get_dbias_vol_gap(void)
+{
+    return EFUSE.rd_mac_sys5.lp_hp_dbias_vol_gap;
+}
+
 FORCE_INLINE_ATTR uint32_t pmu_ll_lp_get_interrupt_raw(pmu_dev_t *hw)
 {
     return hw->lp_ext.int_raw.val;