CODEOWNERS: remove @mbolivar from STM32 SPI

I'm no longer working on this driver.

Signed-off-by: Marti Bolivar <[email protected]>

Author: Marti Bolivar

CODEOWNERS

@@ -78,7 +78,7 @@ drivers/serial/uart_altera_jtag.c        @ramakrishnapallala
 drivers/serial/uart_riscv_qemu.c         @fractalclone
 drivers/net/slip/*                       @jukkar @tbursztyka
 drivers/spi/*                            @tbursztyka
-drivers/spi/spi_ll_stm32.*               @superna9999 @mbolivar
+drivers/spi/spi_ll_stm32.*               @superna9999
 drivers/timer/altera_avalon_timer.c      @ramakrishnapallala
 drivers/timer/pulpino_timer.c            @fractalclone
 drivers/timer/riscv_machine_timer.c      @fractalclone