boards: arm: efr32bg: list SPI in documentation

Add entry for SPI in efr32bg_sltb010a documentation and twister metadata
yaml file.

Signed-off-by: Pawel Czarnecki <[email protected]>

Author: lpawelcz

boards/arm/efr32bg_sltb010a/doc/index.rst

@@ -62,6 +62,8 @@ The efr32bg_sltb010a board configuration supports the following hardware feature
 +-----------+------------+-------------------------------------+
 | COUNTER   | on-chip    | stimer                              |
 +-----------+------------+-------------------------------------+
+| SPI(M/S)  | on-chip    | spi                                 |
++-----------+------------+-------------------------------------+
 | FLASH     | on-chip    | flash memory                        |
 +-----------+------------+-------------------------------------+
 | GPIO      | on-chip    | gpio                                |

boards/arm/efr32bg_sltb010a/efr32bg_sltb010a.yaml

@@ -13,6 +13,7 @@ supported:
   - gpio
   - uart
   - i2c
+  - spi
 testing:
   ignore_tags:
     - net