plat/arm: Increase size of firmware configuration area

plat/arm: Increase size of firmware configuration area

Increased the size of firmware configuration area to accommodate
all configs.

Updated maximum size of following bootloaders due to increase
in firmware configs size and addition of the code in the BL2.

1. Increased maximum size of BL2 for Juno platform in no
   optimisation case.
2. Reduced maximum size of BL31 for fvp and Juno platform.
3. Reduced maximum size of BL32 for Juno platform.

Change-Id: Ifba0564df0d1fe86175bed9fae87fdcf013b1831
Signed-off-by: Manish V Badarkhe <Manish.Badarkhe@arm.com>