configs/ti_am64x_sk_defconfig: drop redundant defconfig choice

The defconfig choice is the default one, so it is redundant and can be
removed without effect.

Signed-off-by: Romain Naour <romain.naour@smile.fr>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>

configs/ti_am64x_sk_defconfig

@@ -24,7 +24,6 @@ BR2_TARGET_OPTEE_OS=y
 BR2_TARGET_OPTEE_OS_PLATFORM="k3"
 BR2_TARGET_TI_K3_IMAGE_GEN=y
 BR2_TARGET_TI_K3_IMAGE_GEN_SOC_AM64X=y
-BR2_TARGET_TI_K3_IMAGE_GEN_SECTYPE_GP=y
 BR2_TARGET_TI_K3_R5_LOADER=y
 BR2_TARGET_TI_K3_R5_LOADER_BOARD_DEFCONFIG="am64x_evm_r5"
 BR2_TARGET_UBOOT=y