Summary of changes: - bootloader_clock split into *_clock_init and *_clock_loader. Only esp_clk_apb_freq is in *_clock_loader. - bootloader_common moved out of loader; functions needed in loader (or, referenced from bootloader_utility) were moved into bootloader_common_loader.c. - assert and abort moved into bootloader_panic, made part of the loader - rtc_clk and rtc_time made part of loader