make freertos source unmodified to ease the upgrade process later

use CGU_GetPCLKFrequency as configCPU_CLOCK_HZ for lpc43xx using with freeRTOS
move portmarco.h include to FreeRTOSConfig.h to have untouched version of freertos
add a readme.md to vendor/freertos
refractor usbh.c, increase POWER_STABLE_DELAY = 500, RESET_DELAY = 200
fix bug with hub, only handle 1 port at a time when reading hub status change endpoint --> other port will be handled in the next cycle

demos/host/host_cmsis_rtx/host_cmsis_rtx.uvopt

@@ -638,10 +638,10 @@
       <FileType>1</FileType>
       <tvExp>0</tvExp>
       <Focus>0</Focus>
-      <ColumnNumber>27</ColumnNumber>
+      <ColumnNumber>0</ColumnNumber>
       <tvExpOptDlg>0</tvExpOptDlg>
       <TopLine>97</TopLine>
-      <CurrentLine>98</CurrentLine>
+      <CurrentLine>102</CurrentLine>
       <bDave2>0</bDave2>
       <PathWithFileName>..\src\main.c</PathWithFileName>
       <FilenameWithoutPath>main.c</FilenameWithoutPath>
@@ -1528,7 +1528,7 @@
       <Focus>0</Focus>
       <ColumnNumber>0</ColumnNumber>
       <tvExpOptDlg>0</tvExpOptDlg>
-      <TopLine>147</TopLine>
+      <TopLine>149</TopLine>
       <CurrentLine>151</CurrentLine>
       <bDave2>0</bDave2>
       <PathWithFileName>..\..\..\mcu\lpc43xx\keil\startup_LPC43xx.s</PathWithFileName>