Add the Denali disk driver.

Begin enumerating information from the PCI structure and HBA AHCI
structures.

Currently the PCI structure address is hardcoded but it should be
passed via a capability from the init process in the future.

sys/denali/CMakeLists.txt

@@ -0,0 +1,17 @@
+add_executable(denali
+  ahci/ahci_driver.cpp
+  denali.cpp)
+
+
+target_include_directories(denali
+   PRIVATE ${CMAKE_CURRENT_SOURCE_DIR})
+
+target_link_libraries(denali
+  cxx
+  mammoth_lib
+  )
+
+set_target_properties(denali PROPERTIES
+  COMPILE_FLAGS "${CMAKE_CXX_FLAGS} ${BASE_COMPILE_FLAGS}"
+  LINK_FLAGS "${CMAKE_EXE_LINK_FLAGS} ${BASE_LINK_FLAGS}"
+  )