platform: msm8952: add support for display clocks for 8956

msm8956 has a different clock plan for MDP clock when compared
to msm8952 and this includes GPLL6. msm8956 supports two DSI
devices. Add support for MDP clock, escape clock for DSI1
controller and update the 8952 clock header with the register
offsets for DSI1 clocks.

Change-Id: I9dd7f59f908f98f7dbf99ff277015f3ec4c4f172
diff --git a/platform/msm8952/include/platform/iomap.h b/platform/msm8952/include/platform/iomap.h
index 8ea20f4..003050a 100644
--- a/platform/msm8952/include/platform/iomap.h
+++ b/platform/msm8952/include/platform/iomap.h
@@ -99,6 +99,7 @@
 #define APCS_CLOCK_BRANCH_ENA_VOTE         (CLK_CTL_BASE + 0x45004)
 #define GPLL4_MODE                         (CLK_CTL_BASE + 0x24000)
 #define GPLL4_STATUS                       (CLK_CTL_BASE + 0x24024)
+#define GPLL6_STATUS                       (CLK_CTL_BASE + 0x3701C)
 
 /* SDCC */
 #define SDC1_HDRV_PULL_CTL                 (TLMM_BASE_ADDR + 0x10A000)