drivers: Return correct erorr codes in SSD1673 driver
drivers: Return correct erorr codes in SSD1673 driver

Return correct error codes in SSD1673 driver instead of -1

Signed-off-by: Jan Van Winkel <d648848808a4d751aff880668aa63d2d9d94a5a4@dxplore.eu>

Vudentz/zephyr,punitvara/zephyr,GiulianoFranchetto/zephyr,galak/zephyr,ldts/zephyr,ldts/zephyr,GiulianoFranchetto/zephyr,finikorg/zephyr,galak/zephyr,galak/zephyr,zephyrproject-rtos/zephyr,ldts/zephyr,punitvara/zephyr,nashif/zephyr,ldts/zephyr,GiulianoFranchetto/zephyr,nashif/zephyr,finikorg/zephyr,explora26/zephyr,GiulianoFranchetto/zephyr,explora26/zephyr,nashif/zephyr,Vudentz/zephyr,punitvara/zephyr,Vudentz/zephyr,zephyrproject-rtos/zephyr,GiulianoFranchetto/zephyr,galak/zephyr,zephyrproject-rtos/zephyr,explora26/zephyr,finikorg/zephyr,zephyrproject-rtos/zephyr,Vudentz/zephyr,nashif/zephyr,zephyrproject-rtos/zephyr,punitvara/zephyr,Vudentz/zephyr,galak/zephyr,punitvara/zephyr,explora26/zephyr,ldts/zephyr,finikorg/zephyr,finikorg/zephyr,explora26/zephyr,nashif/zephyr,Vudentz/zephyr