增加kernel 設定和找SPI flash

週末趁著有高速電腦可以用趕快編kernel，
加了下列幾項

== System type

==== Timer and clock configuration  --->

Tickless System (Dynamic Ticks)

==== CPU Frequency scaling  --->

======Default CPUFreq governor

defautl scaling governor: conservative

'conservative' cpufreq governor

STMicroelectronics CPU Frequency driver

==Power management options

==== Power Management support

Power Management support

Suspend to RAM and standby (NEW)

Run-time PM core functionality (NEW)

CPU idle PM support

自動調整CPU頻率生效了，
# cat /sys/devices/system/cpu/cpu0/cpufreq/scaling_cur_freq
56250
不過我比較想要用 Ondemand governor，
有工作就馬上用全力處理完再來休息。

繼續挖GPIO

在GPIO LED初步完成控制後，下一步找 reset 按鈕。

同樣在 board/st/pdk7105/swUpdate.c 中找到 reset 按鈕相關：
static int check_key_press(void)
{
        int count,cur_key,next_key,led;

        led=0x00;
        count=7;
        cur_key=STPIO_GET_PIN(PIO0_BASSADDRESS, 1);