clk: samsung: exynos5420: update clocks for GSCL and MSCL blocks

This patch adds the missing GSCL and MSCL block clocks
and corrects some wrong parent-child relationships.

Signed-off-by: Rahul Sharma <rahul.sharma@samsung.com>
Signed-off-by: Shaik Ameer Basha <shaik.ameer@samsung.com>
Signed-off-by: Tomasz Figa <t.figa@samsung.com>