board: phytec: imx93: Add phyCORE-i.MX 93 support for all SOM variants

The phyCORE-i.MX 93 is available in various variants (e.g. different ram
sizes, eMMC HS400 yes/no). Enable hardware introspection for the
imx93-phyboard-segin_defconfig, so that during startup the SOM module
variant can be detected, and the hardware can be configured accordingly.
The resulting SPL and u-boot binary shall able to boot each
phyCORE-i.MX 93 module variant on each carrier board. Finally rename
imx93-phyboard-segin_defconfig to imx93-phycore_defconfig, to highlight
its SOM scope.

Signed-off-by: Christoph Stoidner <c.stoidner@phytec.de>
Reviewed-by: Wadim Egorov <w.egorov@phytec.de>
Reviewed-by: Yannic Moog <y.moog@phytec.de>
diff --git a/doc/board/phytec/index.rst b/doc/board/phytec/index.rst
index 99848a9..fa30697 100644
--- a/doc/board/phytec/index.rst
+++ b/doc/board/phytec/index.rst
@@ -7,7 +7,7 @@
    :maxdepth: 2
 
    imx8mm-phygate-tauri-l
-   imx93-phyboard-segin
+   imx93-phycore
    phycore-am62x
    phycore-am64x
    phycore-imx8mm