ls1021atsn: Suggest the NXP RCW github repo

As explained in the text at the bottom of the page
https://source.codeaurora.org/external/qoriq/qoriq-components/rcw:

"QUIC repositories on this site will not receive any updates after
March 31, 2022, and will be deleted on March 31, 2023."

Point to the NXP RCW github repo instead.

Signed-off-by: Fabio Estevam <festevam@denx.de>
Reviewed-by: Vladimir Oltean <olteanv@gmail.com>
Signed-off-by: Peng Fan <peng.fan@nxp.com>
diff --git a/board/freescale/ls1021atsn/README.rst b/board/freescale/ls1021atsn/README.rst
index cdec02f..cd12291 100644
--- a/board/freescale/ls1021atsn/README.rst
+++ b/board/freescale/ls1021atsn/README.rst
@@ -50,7 +50,7 @@
 
 For the QSPI flash, first obtain the Reset Configuration Word binary for
 bootimg from the QSPI flash from the rcw project
-(https://source.codeaurora.org/external/qoriq/qoriq-components/rcw)::
+(https://github.com/nxp-qoriq/rcw)::
 
   make -j 8 && sudo cp ls1021atsn/SSR_PNS_30/rcw_1200_qspiboot.bin.swapped /srv/tftpboot/