include: Add function prototype to detect platform and calculate the boot mask

Add function to detect platform for MSM8909, based on the chip id read from
SMEM.Also, add prototype for the function to decide the boot device mask, for
the value read from the boot config register.

Change-Id: I75bdf86a0e8e07cd31d7e9634245dd6c39123c86
diff --git a/include/platform.h b/include/platform.h
index a76c68b..c2fac94 100644
--- a/include/platform.h
+++ b/include/platform.h
@@ -60,4 +60,6 @@
 uint32_t platform_get_sclk_count(void);
 void clock_config_cdc(uint32_t interface);
 int platform_is_msm8939();
+int platform_is_msm8909();
+int boot_device_mask(int);
 #endif