plat/arm/sgi: allow value of PLAT_MAX_PWR_LVL to be platform specific

For platforms with multi-threaded CPUs, the number of power domains
supported would be more than the value currently defined by
PLAT_MAX_PWR_LVL. So move the PLAT_MAX_PWR_LVL macro to platform
specific code and let the platform define the number of power domain
levels.

Change-Id: I21c0682e62b397860b2999031a0c9c5ce0d28eed
Signed-off-by: Chandni Cherukuri <chandni.cherukuri@arm.com>

plat/arm/board/sgi575/include/platform_def.h

@@ -23,4 +23,6 @@
 /* System power domain level */
 #define CSS_SYSTEM_PWR_DMN_LVL		ARM_PWR_LVL2
 
+#define PLAT_MAX_PWR_LVL		ARM_PWR_LVL1
+
 #endif /* PLATFORM_DEF_H */

plat/arm/board/sgiclarka/include/platform_def.h

@@ -23,4 +23,6 @@
 /* System power domain level */
 #define CSS_SYSTEM_PWR_DMN_LVL		ARM_PWR_LVL2
 
+#define PLAT_MAX_PWR_LVL		ARM_PWR_LVL1
+
 #endif /* PLATFORM_DEF_H */

plat/arm/css/sgi/include/sgi_base_platform_def.h

@@ -119,8 +119,6 @@
 #define PLAT_ARM_NSRAM_BASE		0x06000000
 #define PLAT_ARM_NSRAM_SIZE		0x00080000	/* 512KB */
 
-#define PLAT_MAX_PWR_LVL		U(1)
-
 #define PLAT_ARM_G1S_IRQ_PROPS(grp)	CSS_G1S_IRQ_PROPS(grp)
 #define PLAT_ARM_G0_IRQ_PROPS(grp)	ARM_G0_IRQ_PROPS(grp)