mimxrt1050_evk: Fix setting of JLINK_DEVICE
mimxrt1050_evk: Fix setting of JLINK_DEVICE

The '=' character was incorrectly getting passed to the JLinkGDBServer
device argument, and caused the server to fail to connect to the target.

Signed-off-by: Maureen Helm <87a696db5547fa477bda9f9e0f00013c839c14d3@nxp.com>

finikorg/zephyr,ldts/zephyr,mbolivar/zephyr,mbolivar/zephyr,mbolivar/zephyr,galak/zephyr,explora26/zephyr,zephyriot/zephyr,finikorg/zephyr,ldts/zephyr,nashif/zephyr,explora26/zephyr,kraj/zephyr,kraj/zephyr,zephyriot/zephyr,finikorg/zephyr,GiulianoFranchetto/zephyr,aceofall/zephyr-iotos,finikorg/zephyr,aceofall/zephyr-iotos,finikorg/zephyr,zephyrproject-rtos/zephyr,kraj/zephyr,GiulianoFranchetto/zephyr,zephyrproject-rtos/zephyr,galak/zephyr,Vudentz/zephyr,punitvara/zephyr,nashif/zephyr,ldts/zephyr,zephyrproject-rtos/zephyr,zephyrproject-rtos/zephyr,zephyriot/zephyr,zephyriot/zephyr,galak/zephyr,ldts/zephyr,ldts/zephyr,GiulianoFranchetto/zephyr,aceofall/zephyr-iotos,Vudentz/zephyr,Vudentz/zephyr,kraj/zephyr,punitvara/zephyr,kraj/zephyr,Vudentz/zephyr,nashif/zephyr,GiulianoFranchetto/zephyr,aceofall/zephyr-iotos,punitvara/zephyr,mbolivar/zephyr,explora26/zephyr,nashif/zephyr,Vudentz/zephyr,zephyriot/zephyr,galak/zephyr,mbolivar/zephyr,aceofall/zephyr-iotos,galak/zephyr,explora26/zephyr,Vudentz/zephyr,explora26/zephyr,nashif/zephyr,GiulianoFranchetto/zephyr,zephyrproject-rtos/zephyr,punitvara/zephyr,punitvara/zephyr