arm64: versal: Add missing prototypes

arm64: versal: Add missing prototypes

Add missing prototypes to fix the below sparse warnings
1. warning: no previous prototype for 'set_r5_halt_mode'
[-Wmissing-prototypes]
2. warning: no previous prototype for 'set_r5_tcm_mode'
[-Wmissing-prototypes]
3. warning: no previous prototype for 'release_r5_reset'
[-Wmissing-prototypes]
4.warning: no previous prototype for 'enable_clock_r5'
[-Wmissing-prototypes]

Signed-off-by: Algapally Santosh Sagar <santoshsagar.algapally@amd.com>
Signed-off-by: Ashok Reddy Soma <ashok.reddy.soma@amd.com>
Link: https://lore.kernel.org/r/20230609090531.31794-3-ashok.reddy.soma@amd.com
Signed-off-by: Michal Simek <michal.simek@amd.com>