ARM: EXYNOS: use four additional chipid bits to identify EXYNOS family

ARM: EXYNOS: use four additional chipid bits to identify EXYNOS family

Use chipid[27:20] bits to identify the EXYNOS family while setting
up the serial port during the uncompression setup. This uses four
additional bits of chipid to identify the EXYNOS family since this
is required for identifying EXYNOS5420 SoC.

Change-Id: Ic7cc14e68d16ae3da2a7d2177b40e40b0295d9a8
Signed-off-by: Chander Kashyap <chander.kashyap@linaro.org>
Signed-off-by: Thomas Abraham <thomas.abraham@linaro.org>
Reviewed-by: Tomasz Figa <t.figa@samsung.com>
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>