platsupport,rtc: Tweak code to suppress warning

Compiler is happier if array indexing is used instead of pointer
arithmetic when it is a string.

Signed-off-by: Kent McLeod <kent@kry10.com>

libplatsupport/src/plat/pc99/rtc.c

diff --git a/libplatsupport/src/plat/pc99/rtc.c b/libplatsupport/src/plat/pc99/rtc.c
index 7e02576..44b22cb 100644
--- a/libplatsupport/src/plat/pc99/rtc.c
+++ b/libplatsupport/src/plat/pc99/rtc.c
@@ -20,7 +20,7 @@
 static inline int current_year()
 {
 #ifdef __DATE__
-    return atoi(__DATE__ + 7);
+    return atoi(&__DATE__[7]);
 #else
     return 2014;
 #endif
@@ -138,6 +138,6 @@
         ZF_LOGE("ACPI has no FADT header. Your BIOS is broken");
         return 0;
     }
-    acpi_fadt_t *fadt = (acpi_fadt_t*)header;
+    acpi_fadt_t *fadt = (acpi_fadt_t *)header;
     return fadt->century;
 }