ARM: exynos: Remove outdated maintainer information

The current maintainers are specified in MAINTAINERS file, so remove
in-sources information with outdated e-mail address (Thomas Abraham's
email does not work, Kukjin Kim uses @kernel.org).
Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>

arch/arm/mach-exynos/exynos.c

@@ -190,8 +190,6 @@ static void __init exynos_dt_fixup(void)
 }
 
 DT_MACHINE_START(EXYNOS_DT, "SAMSUNG EXYNOS (Flattened Device Tree)")
-	/* Maintainer: Thomas Abraham <thomas.abraham@linaro.org> */
-	/* Maintainer: Kukjin Kim <kgene.kim@samsung.com> */
 	.l2c_aux_val	= 0x3c400001,
 	.l2c_aux_mask	= 0xc20fffff,
 	.smp		= smp_ops(exynos_smp_ops),