Remove unnecessary paths

Removing the paths on certain commands (e.g., ppu32-gcc) and removing
-I/usr/include makes it possible to build for Cell on both PowerPC and
x86 hosts.

configs/linux-cell

@@ -6,14 +6,14 @@ CONFIG_NAME = linux-cell
 
 
 # Compiler and flags
-CC = /usr/bin/ppu32-gcc
-CXX = /usr/bin/ppu32-g++
+CC = ppu32-gcc
+CXX = ppu32-g++
 
 # Cell SDK location
 SDK = /opt/ibm/cell-sdk/prototype/sysroot/usr
 
 
-CFLAGS = -g -W -Winline -fPIC -m32 -mabi=altivec -maltivec -I. -I/usr/include -I$(SDK)/include -DGALLIUM_CELL
+CFLAGS = -g -W -Winline -fPIC -m32 -mabi=altivec -maltivec -I. -I$(SDK)/include -DGALLIUM_CELL
 
 CXXFLAGS = $(CFLAGS)
 
@@ -31,14 +31,14 @@ GL_LIB_DEPS = $(EXTRA_LIB_PATH) -lX11 -lXext -lm -lpthread \
 
 ### SPU stuff
 
-SPU_CC = /usr/bin/spu-gcc
+SPU_CC = spu-gcc
 
 SPU_CFLAGS = -g -W -Wall -Winline -Wmissing-prototypes -Wno-main -I. -I $(SDK)/spu/include -include spu_intrinsics.h -I $(TOP)/src/mesa/
 
 SPU_LFLAGS = -L$(SDK)/spu/lib -Wl,-N -lmisc
 
-SPU_AR = /usr/bin/ar
+SPU_AR = ppu-ar
 SPU_AR_FLAGS = -qcs
 
-SPU_EMBED = /usr/bin/embedspu
+SPU_EMBED = ppu32-embedspu
 SPU_EMBED_FLAGS = -m32