Rename all Silicon Labs dev kits to always use the official kit name
as board target name. Previous kit names used various naming schemes,
including putting part of the SoC name in the board name. With HWMv2,
SoC names (if needed) should go in the SoC board qualifier.
Use HWMv2 revisions for the two variants of SLTB010A.
Split the xG27 Dev Kit from the EFR32BG22 Thunderboard. This attempt
at deduplication is confusing due to the very different kit names
and use of different ICs (BG22 vs BG27), and was not continued with
the xG24 Dev Kit, meaning that it wasn't consistent.
Signed-off-by: Aksel Skauge Mellbye <aksel.mellbye@silabs.com>
