feat(driver): BitScrambler support

This adds an assembler for the BitScrambler assembly language,
plus unit tests for it. It also adds the loopback driver,
which can do BitScrambler operations on memory-to-memory
transfers. Documentation is also included.

components/esp_driver_bitscrambler/CMakeLists.txt

@@ -0,0 +1,29 @@
+idf_build_get_property(target IDF_TARGET)
+
+set(srcs)
+set(include_dirs)
+set(priv_requires)
+
+set(my_priv_requires "soc" "hal" "esp_hw_support" "esp_mm")
+
+if(CONFIG_SOC_BITSCRAMBLER_SUPPORTED)
+    list(APPEND srcs "bitscrambler.c" "bitscrambler_loopback.c")
+    list(APPEND include_dirs "include")
+endif()
+
+# Note that (according to the docs) "The values of REQUIRES and PRIV_REQUIRES
+# should not depend on any configuration choices (CONFIG_xxx macros)." We work
+# around that by setting the actual priv_requires value in the target checks,
+# rather than make it depend on CONFIG_SOC_BITSCRAMBLER_SUPPORTED.
+
+if(target STREQUAL "esp32p4")
+    list(APPEND srcs "bitscrambler_esp32p4.c")
+    set(priv_requires ${my_priv_requires})
+endif()
+
+
+idf_component_register(SRCS ${srcs}
+                    PRIV_REQUIRES ${priv_requires}
+                    INCLUDE_DIRS ${include_dirs}
+                    PRIV_INCLUDE_DIRS "priv_include"
+                    )