platform: msm_shared: correct parameter type in encrypt_scm call
platform: msm_shared: correct parameter type in encrypt_scm call

In encrypt_scm armv8 call TZ expects both parameters types
as read-write buffer/address of location. Change type of
length parameter to read-write buffer type.

Change-Id: I06272524446eec98f420c41bf6a08e23631cb08f

CanarySolutions/little-kernel,CanarySolutions/little-kernel,Foxda-Tech/polaris-bootable-bootloader-lk,CanarySolutions/little-kernel,Foxda-Tech/polaris-bootable-bootloader-lk,Foxda-Tech/polaris-bootable-bootloader-lk,efidroid/lk,efidroid/lk,efidroid/lk,Foxda-Tech/polaris-bootable-bootloader-lk,Foxda-Tech/polaris-bootable-bootloader-lk,efidroid/lk,CanarySolutions/little-kernel,efidroid/lk,CanarySolutions/little-kernel