ulp: refactor ulp component

This commit refactors the ulp component.
Files are now divided based on type of ulp, viz., fsm or risc-v.
Files common to both are maintained in the ulp_common folder.

This commit also adds menuconfig options for ULP within the ulp
component instead of presenting target specific configuations for ulp.

components/ulp/ulp_riscv/include/ulp_riscv.h

@@ -0,0 +1,69 @@
+/*
+ * SPDX-FileCopyrightText: 2021-2022 Espressif Systems (Shanghai) CO LTD
+ *
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+#pragma once
+#include <stdint.h>
+#include <stddef.h>
+#include <stdlib.h>
+#include "esp_err.h"
+#include "ulp_common.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+/**
+ * @brief Run the program loaded into RTC memory
+ * @return  ESP_OK on success
+ */
+esp_err_t ulp_riscv_run(void);
+
+/**
+ * @brief Load ULP-RISC-V program binary into RTC memory
+ *
+ * Different than ULP FSM, the binary program has no special format, it is the ELF
+ * file generated by RISC-V toolchain converted to binary format using objcopy.
+ *
+ * Linker script in components/ulp/ld/ulp_riscv.ld produces ELF files which
+ * correspond to this format. This linker script produces binaries with load_addr == 0.
+ *
+ * @param program_binary pointer to program binary
+ * @param program_size_bytes size of the program binary
+ * @return
+ *      - ESP_OK on success
+ *      - ESP_ERR_INVALID_SIZE if program_size_bytes is more than 8KiB
+ */
+esp_err_t ulp_riscv_load_binary(const uint8_t* program_binary, size_t program_size_bytes);
+
+/**
+ * @brief Stop the ULP timer
+ *
+ * @note This will stop the ULP from waking up if halted, but will not abort any program
+ *       currently executing on the ULP.
+ */
+void ulp_riscv_timer_stop(void);
+
+
+/**
+ * @brief Resumes the ULP timer
+ *
+ * @note This will resume an already configured timer, but does no other configuration
+ *
+ */
+void ulp_riscv_timer_resume(void);
+
+
+/**
+ * @brief Halts the program currently running on the ULP-RISC-V
+ *
+ * @note  Program will restart at the next ULP timer trigger if timer is still running.
+ *        If you want to stop the ULP from waking up then call ulp_riscv_timer_stop() first.
+ */
+void ulp_riscv_halt(void);
+
+#ifdef __cplusplus
+}
+#endif