resource: Fix build warning for memory/process resource driver

resource: Fix build warning for memory/process resource driver

- Build warning 1
src/resource/resource-memory.c:42:10: warning: implicit declaration
  of function 'kernel_get_memory_total' [-Wimplicit-function-declaration]
[   11s]    42 |   return kernel_get_memory_total();
[   11s]       |          ^~~~~~~~~~~~~~~~~~~~~~~
src/resource/resource-memory.c:44:10: warning: implicit declaration
  of function 'kernel_get_memory_info' [-Wimplicit-function-declaration]
[   11s]    44 |   return kernel_get_memory_info(PROC_MEM_INFO_MEM_AVAILABLE);

- Build warning 2
src/resource/resource-process.c:452:19: warning: unused variable 'memory' [-Wunused-variable]
[   12s]   452 |  struct resource *memory;

Change-Id: I2a473453fb02fc7dd1eb8319474fe9e8633ea2a0
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>