axs103: Clean-up smp_kick_all_cpus()

* Rely on default pulse polarity value
 * Don't mess with "multicore" value as it doesn't affect execution

In essence we now do a bare minimal stuff:
 1) Select HS38x2_1 with CORE_SEL=1 bits
 2) Select "manual" core start (via CREG) with START_MODE=0
 3) Generate cpu_start pulse with START=1

Signed-off-by: Alexey Brodkin <abrodkin@synopsys.com>

board/synopsys/axs10x/axs10x.c

@@ -61,16 +61,14 @@ void smp_kick_all_cpus(void)
 {
 /* CPU start CREG */
 #define AXC003_CREG_CPU_START	0xF0001400
-
 /* Bits positions in CPU start CREG */
 #define BITS_START	0
-#define BITS_POLARITY	8
+#define BITS_START_MODE	4
 #define BITS_CORE_SEL	9
-#define BITS_MULTICORE	12
-
-#define CMD	(1 << BITS_MULTICORE) | (1 << BITS_CORE_SEL) | \
-		(1 << BITS_POLARITY) | (1 << BITS_START)
 
-	writel(CMD, (void __iomem *)AXC003_CREG_CPU_START);
+	int cmd = readl((void __iomem *)AXC003_CREG_CPU_START);
+	cmd |= (1 << BITS_CORE_SEL) | (1 << BITS_START);
+	cmd &= ~(1 << BITS_START_MODE);
+	writel(cmd, (void __iomem *)AXC003_CREG_CPU_START);
 }
 #endif