[U-Boot] Making U-Boot smaller

[Eugeniu Rosca]

cc: Yamada-san

I dream of a (Kconfig/Kbuild-assisted) bloaty-like output [1] which
would point out the culprit configs. This is hardly achievable, but
looks good on the paper!

      CONFIG           FILE SIZE
  ------------       --------------
  CONFIG_FEATURE_A    10.7Mi  37.1%
  CONFIG_FEATURE_B    5.39Mi  18.6%
  CONFIG_FEATURE_C    4.48Mi  15.5%
  CONFIG_FEATURE_D    1.86Mi   6.4%
  CONFIG_FEATURE_E    1.67Mi   5.8%
  CONFIG_FEATURE_F    1.61Mi   5.6%
  CONFIG_FEATURE_G     856Ki   2.9%
  CONFIG_FEATURE_H     470Ki   1.6%
  ....
  TOTAL               28.9Mi 100.0%

[1] https://github.com/google/bloaty

-- 
Best regards,
Eugeniu