fdts: use scmi_dvfs clock index 1 for cores 4-7
fdts: use scmi_dvfs clock index 1 for cores 4-7

This allows Matterhorn cores to operate at their optimal OPPs.

Signed-off-by: Usama Arif <2c149411f3e2627c4e078c64c194672b53885363@arm.com>
Change-Id: I2e1b784da10154a1f1f65dd0e3a39213e7683116

achingupta/arm-trusted-firmware,achingupta/arm-trusted-firmware