[S] Change in coreboot[main]: soc/mediatek/mt8196: Initialize SSPM

[Yidi Lin (Code Review)]

Attention is currently required from: Hung-Te Lin, Jarried Lin, Kenji Yu, Yu-Ping Wu.

Yidi Lin has posted comments on this change by Jarried Lin. ( https://review.coreboot.org/c/coreboot/+/85516?usp=email )

Change subject: soc/mediatek/mt8196: Initialize SSPM
......................................................................

Patch Set 11:

(3 comments)

File src/soc/mediatek/mt8196/include/soc/mt8196_sspm.h:

https://review.coreboot.org/c/coreboot/+/85516/comment/2402375b_4fa8826a?usp... :
PS11, Line 6: #include <soc/addressmap.h>
            : 
            : #define SSPM_SRAM_CON		(SPM_BASE + 0xEE4)
            : #define SPM_PRJ_CODE		0xB160001
            : #define SSPM_SRAM_SLEEP_B	0x10
            : #define SSPM_SRAM_ISOINT_B	0x2
Move to `mt8196/sspm_sram.c`.

https://review.coreboot.org/c/coreboot/+/85516/comment/51fe9d4f_c09ff629?usp... :
PS11, Line 13: void sspm_enable_sram(void);
1. Move to `common/soc/include/sspm.h`
2. Add a weak function in `common/sspm.c`
```
__weak void sspm_enable_sram(void) { /* do nothing */ }
```

in `common/sspm.c`

```
void sspm_init()
{
    sspm_enable_sram();
    ...
    ...
}
```

File src/soc/mediatek/mt8196/sspm.c:

https://review.coreboot.org/c/coreboot/+/85516/comment/f3b64c47_36027286?usp... :
PS11, Line 4: mt8196_sspm
sspm.h