This patch is used to fix remaining non compliant code for Intel
SocFPGA's mailbox driver. These changes include:
- adding integer literal for unsigned constant
- fix non-boolean controlling expression
- add braces even on conditional single statement bodies

Signed-off-by: Abdul Halim, Muhammad Hadi Asyrafi <muhammad.hadi.asyrafi.abdul.halim@intel.com>
Change-Id: I0f8fd96a3540f35ee102fd2f2369b76fa73e39e1