Tegra: Split tegra_get_chip_type() into soc & sku funcs

As suggested by Stephen Warren, use tegra_get_chip() to return
the pure CHIPID for a Tegra SoC (i.e. 0x20 for Tegra20, 0x30 for
Tegra30, etc.) and rename tegra_get_chip_type() to reflect its true
function, i.e. tegra_get_chip_sku(), which returns an ID like
TEGRA_SOC_T25, TEGRA_SOC_T33, etc.

Signed-off-by: Tom Warren <twarren@nvidia.com>
Reviewed-by: Stephen Warren <swarren@nvidia.com>
diff --git a/arch/arm/cpu/tegra20-common/pmu.c b/arch/arm/cpu/tegra20-common/pmu.c
index 2282953..4c5a533 100644
--- a/arch/arm/cpu/tegra20-common/pmu.c
+++ b/arch/arm/cpu/tegra20-common/pmu.c
@@ -44,7 +44,7 @@
 	int core, cpu, bus;
 
 	/* by default, the table has been filled with T25 settings */
-	switch (tegra_get_chip_type()) {
+	switch (tegra_get_chip_sku()) {
 	case TEGRA_SOC_T20:
 		core = VDD_CORE_NOMINAL_T20;
 		cpu = VDD_CPU_NOMINAL_T20;
@@ -54,7 +54,7 @@
 		cpu = VDD_CPU_NOMINAL_T25;
 		break;
 	default:
-		debug("%s: Unknown chip type\n", __func__);
+		debug("%s: Unknown SKU id\n", __func__);
 		return -1;
 	}