WDT: Add LL and HAL for watchdog timers

This commit updates the watchdog timers (MWDT and RWDT)
in the following ways:

- Add seprate LL for MWDT and RWDT.
- Add a combined WDT HAL for all Watchdog Timers
- Update int_wdt.c and task_wdt.c to use WDT HAL
- Remove most dependencies on LL or direct register access
  in other components. They will now use the WDT HAL
- Update use of watchdogs (including RTC WDT) in bootloader and
  startup code to use the HAL layer.

components/bootloader/subproject/main/ld/esp32/bootloader.ld

@@ -52,7 +52,7 @@ SECTIONS
     *libbootloader_support.a:secure_boot_signatures.*(.literal .text .literal.* .text.*)
     *libmicro-ecc.a:*.*(.literal .text .literal.* .text.*)
     *libspi_flash.a:*.*(.literal .text .literal.* .text.*)
-    *libsoc.a:rtc_wdt.*(.literal .text .literal.* .text.*)
+    *libsoc.a:wdt_hal_iram.*(.literal .text .literal.* .text.*)
     *libsoc.a:rtc_clk.*(.literal .text .literal.* .text.*)
     *libefuse.a:*.*(.literal .text .literal.* .text.*)
     *(.fini.literal)