Tegra: implement common handler `plat_get_target_pwr_state()`

This patch adds a platform handler to calculate the proper target power
level at the specified affinity level.

Tegra platforms assign a local state value in order of decreasing depth
of the power state i.e. for two power states X & Y, if X < Y then X
represents a shallower power state than Y. As a result, the coordinated
target local power state for a power domain will be the maximum of the
requested local power state values.

Change-Id: I67360684b7f5b783fcfdd605b96da5375fa05417
Signed-off-by: Varun Wadekar <vwadekar@nvidia.com>

plat/nvidia/tegra/common/tegra_common.mk

@@ -52,7 +52,6 @@ BL31_SOURCES		+=	drivers/arm/gic/gic_v2.c			\
 				drivers/delay_timer/delay_timer.c		\
 				drivers/ti/uart/aarch64/16550_console.S		\
 				plat/common/aarch64/platform_mp_stack.S		\
-				plat/common/plat_psci_common.c			\
 				${COMMON_DIR}/aarch64/tegra_helpers.S		\
 				${COMMON_DIR}/drivers/pmc/pmc.c			\
 				${COMMON_DIR}/tegra_bl31_setup.c		\

plat/nvidia/tegra/common/tegra_pm.c

@@ -318,3 +318,24 @@ int plat_setup_psci_ops(uintptr_t sec_entrypoint,
 
 	return 0;
 }
+
+/*******************************************************************************
+ * Platform handler to calculate the proper target power level at the
+ * specified affinity level
+ ******************************************************************************/
+plat_local_state_t plat_get_target_pwr_state(unsigned int lvl,
+					     const plat_local_state_t *states,
+					     unsigned int ncpu)
+{
+	plat_local_state_t target = PLAT_MAX_RET_STATE, temp;
+
+	assert(ncpu);
+
+	do {
+		temp = *states++;
+		if ((temp > target) && (temp != PLAT_MAX_OFF_STATE))
+			target = temp;
+	} while (--ncpu);
+
+	return target;
+}