Remove _tzc_get_max_top_addr() function

This function was needed at the time where we didn't have the
compiler_rt lib. An AArch32-specific variant was provided to handle
the 64-bit shift operation in 32-bit. This is no longer needed.

Change-Id: Ibab709a95e3a723ae2eeaddf873dba70ff2012b3
Signed-off-by: Sandrine Bailleux <sandrine.bailleux@arm.com>
diff --git a/drivers/arm/tzc/tzc400.c b/drivers/arm/tzc/tzc400.c
index 763eba7..d27b010 100644
--- a/drivers/arm/tzc/tzc400.c
+++ b/drivers/arm/tzc/tzc400.c
@@ -182,8 +182,8 @@
 	 * Do address range check based on TZC configuration. A 64bit address is
 	 * the max and expected case.
 	 */
-	assert(((region_top <= _tzc_get_max_top_addr(tzc400.addr_width)) &&
-		(region_base < region_top)));
+	assert((region_top <= (UINT64_MAX >> (64U - tzc400.addr_width))) &&
+		(region_base < region_top));
 
 	/* region_base and (region_top + 1) must be 4KB aligned */
 	assert(((region_base | (region_top + 1U)) & (4096U - 1U)) == 0U);