Change in coreboot[master]: soc/intel/common/block/pcie/rtd3: Add ModPHY power gate support for RTD3

[Cliff Huang (Code Review)]

Attention is currently required from: Maulik V Vaghela, Tim Wawrzynczak, Patrick Rudolph.
Cliff Huang has posted comments on this change. ( https://review.coreboot.org/c/coreboot/+/59855 )

Change subject: soc/intel/common/block/pcie/rtd3: Add ModPHY power gate support for RTD3
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Patch Set 4: Code-Review+1

(1 comment)

File src/soc/intel/common/block/pcie/rtd3/rtd3.c:

https://review.coreboot.org/c/coreboot/+/59855/comment/d88e4ca2_fed34400 
PS2, Line 238: 	static bool mutex_created;
> Why we need to initialize to `false` ? Default value itself is false. Isn't it? […]

This shows that the memory locations used for static variables and space from the stack were '0' at the time. I don't think compiler will add code to initialize with '0's to ensure not getting leftover value from previous use (such as mem test) for the locations that it uses or acquires from the system.